# Snowmobiles: Environmental Standards and Access to National Parks

> Briefs, arguments, decisions, and more.

URL: https://www.frixlaw.com/law-library/documents/crs%3ARL31149

## Record

- **Collection:** Congressional research report
- **Document type:** CRS Report
- **Published:** October 2, 2008
- **Citation:** RL31149

## Text

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Prepared for Members and Committees of Congress

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For at least a decade, the use of snowmobiles in Yellowstone and other national parks has been
controversial because of the potential impacts on wildlife and, until recently, the absence of
standards for snowmobile emissions and noise. The National Park Service has attempted to
address the issue by developing Winter Use Plans that establish regulations and limits at
individual park units. These plans have been the subject of numerous legal challenges. On
September 15, 2008, the U.S. District Court for the District of Columbia vacated the National
Park Service’s most recent Winter Use Plan for Yellowstone National Park. The plan would have
allowed up to 540 snowmobiles per day into the park beginning in the 2008-2009 winter season,
provided that they met noise and emission standards and that the riders were accompanied by
commercial guides. The NPS plan was opposed by environmental groups and the vast majority of
public commenters. With the rule vacated, it is unclear what limits will apply in the coming
winter season.
Current model snowmobiles emit significant quantities of pollution. In one hour, a new model
snowmobile emits as much hydrocarbon as a 2008 model auto emits in about four years (54,000
miles) of driving. The Environmental Protection Agency (EPA) promulgated regulations limiting
air emissions from snowmobiles in 2002, but the regulations have the effect of allowing the
machines to emit as much hydrocarbon pollution in a day as a new auto emits in its lifetime.
Snowmobiles also emit significant amounts of noise. EPA has no snowmobile noise standards.
The National Park Service has allowed snowmobile use in 43 units of the national park system, in
many cases in apparent violation of Executive Orders from the Nixon and Carter years. Outside
of Alaska (where snowmobiles are permitted in most national parks by law), the most popular
national park for snowmobiling has been Yellowstone, which saw more than 87,000 snowmobile
visits in the 2001-2002 winter season. Under the Clinton Administration, the Park Service
decided that the emissions and noise from snowmobiling were incompatible with protecting the
park, and promulgated rules that would have phased out snowmobiles from Yellowstone by the
winter of 2003-2004. The Bush Administration revisited these rules and announced modifications
in March 2003 that would have allowed continued use of snowmobiles. The 2003 rules and the
Clinton Administration action have been the subject of conflicting court rulings: a federal court in
Wyoming has vacated and remanded the Clinton Administration’s phaseout, while a D.C. federal
court has vacated and remanded the Bush Administration rules. For the last four winters,
Yellowstone and two neighboring park units have operated under a temporary plan that permits
720 snowmobiles per day in Yellowstone, but sets standards for their emissions and requires
snowmobilers to be accompanied by commercial guides. Under these rules, snowmobile visits
have declined by two-thirds.
Efforts to reduce snowmobile emissions and noise remain contentious. This report discusses
snowmobile access to the parks, snowmobile emissions, EPA’s emission standards, and
congressional efforts to address these issues.

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Snowmobile Use in National Parks................................................................................................. 1
Park Service Policy on Snowmobile Access ................................................................................... 2
Denali National Park ................................................................................................................. 3
Yellowstone/Grand Teton.......................................................................................................... 4
November 2007 Winter Use Plan.............................................................................................. 7
Clean Air Act and Noise Control Act Regulation............................................................................ 8
Snowmobile Emissions ............................................................................................................. 8
EPA’s 2002 Regulations .......................................................................................................... 10
Reaction to the EPA Standards ................................................................................................ 12
Legislative Issues .......................................................................................................................... 14
Conclusions ................................................................................................................................... 14

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Table 1. Snowmobile Visits to Yellowstone Area Park Units.......................................................... 7
Table 2. EPA and NPS Snowmobile Emission Limits................................................................... 10

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Author Contact Information .......................................................................................................... 15

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D

uring the final year of the Clinton Administration, proposals by the National Park Service
to enforce long-standing policies that regulated the use of snowmobiles in national parks
raised a number of questions regarding the potential regulation of such vehicles. These
questions continue to be debated, as the National Park Service (NPS) explores optional winter use
plans for Yellowstone and other units of the national park system, and as various parties challenge
the actions of the NPS in court.
National Park System units account for only about 3% of the land mass of the United States and
possess few trails and roads suitable for snowmobiles, compared to areas available on other
federal lands; but—for both proponents and opponents—the question of snowmobile access to the
parks has taken on a far greater importance. To the snowmobile industry and to many in
communities neighboring national parks, “Snowmobiling is an important part of the economic
engine that supports northern communities, winter tourism.”1 To environmental groups,
snowmobiling “is one of the most environmentally devastating recreational activities permitted
by the Park Service .... resulting in adverse impacts to Park wildlife, air and water quality,
vegetation, Park ecology, and Park users.”2 Underlying the debate are broader questions
concerning regulation of emissions and noise from the vehicles and the degree to which
restrictions may serve as a precedent or stigma affecting snowmobile and motorized recreation3
use more generally.

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In the 1990s, snowmobiles were allowed access to 43 units of the National Park System,
including such major parks as Yellowstone, Grand Teton, Rocky Mountain, Acadia, Zion, Mount
Rainier, and Sequoia. While numerous park units allowed such access, recreational use of
snowmobiles has not been widespread in the park system as a whole. The National Park Service
administers 391 units (parks, seashores, monuments, etc.). Of these, 348 (89%) have not been
open to snowmobiles. Many units are located in climates unsuitable for them or are too small to
be used for such recreation. Others (e.g., Glacier National Park and Yosemite) have banned
snowmobiles since the 1970s. According to the National Parks Conservation Association, use of
snowmobiles outside of Alaska has mostly been concentrated in five units of the park system:
Yellowstone National Park, Voyageurs National Park, Rocky Mountain National Park, Pictured
Rocks National Lakeshore, and the John D. Rockefeller Memorial Parkway. Yellowstone
accounted for about 40% of the snowmobile visitors at these five parks, with a total of 76,571 in
the 1999-2000 winter season.4

1

Statement of Ed Klim, President, International Snowmobile Manufacturers Association, at U.S. EPA Public Hearing,
Washington, D.C., October 24, 2001.
2
Petition to Prohibit Snowmobiling and Road Grooming in National Parks, submitted to the National Park Service,
January 21, 1999, by Bluewater Network and 60 other environmental groups. A copy of the petition is attached to the
testimony of Sean Smith, Public Lands Director, Bluewater Network, submitted to the Subcommittee on National
Parks, Historic Preservation and Recreation, Senate Energy and Natural Resources Committee, May 25, 2000.
3
Motorized recreation includes all-terrain vehicles, off-road motorcycles, other off-highway vehicles, and personal
watercraft, in addition to snowmobiles.
4
Statement of Kevin Collins, National Parks Conservation Association, Snowmobiles in National Parks, Hearing,
Subcommittee on Tax, Finance and Exports, Small Business Committee, U.S. House of Representatives, July 13, 2000,
at http://www.npca.org/media_center/testimonies/testimony071300.html.

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Comparative data for all five of these units are not available for years after 1999-2000. One of the
five, Rocky Mountain National Park, has closed all but one snowmobile route since 2004—the
one route remaining being a 2-mile trail that provides access to National Forest land heavily used
by snowmobiles. Snowmobile visits to Yellowstone increased during the 2000-2001 and 20012002 winter seasons, peaking at 87,206 in the latter winter. In subsequent years, snowmobile
visitors to Yellowstone plummeted, to a low of 24,049 in 2004-2005. Changes in access policy
(described later in this report) as well as drought and low snow pack in recent years contributed to
the decline. Two other Yellowstone area park units, Grand Teton National Park and the
Rockefeller Memorial Parkway, experienced an even more steep decline, from a combined
35,000 snowmobile visits in 2000-2001 to about 7,500 in 2004-2005.5 Snowmobile visits have
rebounded somewhat since 2004-2005, but in 2007-2008 they remained at only about 35% of
visits in the peak years.6

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Although recreational access by snowmobiles has been permitted in units of the national park
system, the Park Service, in the late 1990s, concluded that such use has generally been in
violation of Executive Orders 11644 and 11989, issued by Presidents Nixon and Carter
respectively. The Nixon Order directed that use of off-road vehicles on public lands “be
controlled and directed so as to protect the resources of those lands, to promote the safety of all
users of those lands, and to minimize conflicts among the various uses of those lands.”7 It
specified that off-road vehicle “areas and trails shall be located in areas of the National Park
system ... only if the respective agency head determines that off-road vehicle use in such locations
will not adversely affect their natural, aesthetic, or scenic values,” and it directed the Park Service
to “monitor the effects of the use of off-road vehicles” and to rescind or limit this use “as
necessary to further the policy of this order.”
In January 1999, the Park Service received a rulemaking petition from the Bluewater Network
and 60 other environmental organizations seeking a ban on snowmobiles from all units of the
National Park Service. In response, the Service surveyed units of the System to assess the extent
to which they were complying with the Executive Orders. According to Interior Department
testimony: “The results graphically demonstrated that the National Park Service was not
complying with its statutory and regulatory mandates.... Consequently, maintaining the status quo
with regard to snowmobiling was simply not an option.”8 On April 27, 2000, the Department of
the Interior and the National Park Service announced that “snowmobiling for general recreational
purposes will be prohibited throughout the Park System, with a limited number of narrow
exceptions.”9 By July 2000, the Department had backed away from its strict enforcement stance
5

Data are available for each of the years 1996-1997 to 2006-2007 in Winter Use Plans, Final Environmental Impact
Statement, Yellowstone and Grand Teton National Parks, John D. Rockefeller, Jr. Memorial Parkway, 2007, Volume
1, pp. 154, 161, at http://www.nps.gov/yell/parkmgmt/upload/vol1_chapters1-3.pdf.
6
National Park Service, NPS Stats, at http://www.nature.nps.gov/stats.
7
Executive Order 11644, “Use of Off-Road Vehicles on the Public Lands,” 37 Federal Register 2877, February 9,
1972.
8
Statement of Donald J. Barry, Assistant Secretary for Fish and Wildlife and Parks, U.S. Department of the Interior,
before the House Committee on Resources, Subcommittee on National Parks and Public Lands, and the Senate
Committee on Energy and Natural Resources, Subcommittee on National Parks, Historic Preservation, and Recreation,
May 25, 2000.
9
U.S. Department of the Interior, Office of the Assistant Secretary, “National Park Service Puts the Brakes on
(continued...)

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with a clarification: there would be no snowmobile ban in park units pending a formal rulemaking
and public comment period, and snowmobile practices prior to the April 2000 announcement (i.e.,
access to more than 40 parks) would continue through the 2000-2001 winter season.10 NPS has
taken no further action to enunciate a general policy.
Since the summer of 2000, the focus has been on Denali National Park in Alaska and the
Yellowstone/Grand Teton area. Both of these areas had been considered exceptions subject to
special consideration even under the April 2000 policy announced by the Park Service. Whether
snowmobile access to these parks will be allowed to continue has generated substantial public
interest.

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In Alaska, vast distances, lack of roads, abundant snow cover, and small dispersed populations
make snow machine use ubiquitous. In general, national parks in Alaska allow snowmobile
access under the provisions of the Alaska National Interest Lands Conservation Act (ANILCA,
P.L. 96-487). However, access to the 2 million acres formerly known as Mt. McKinley National
Park (now the core of Denali National Park) has been an issue. Prior to passage of ANILCA
(1980), snowmobiles had been banned from this park. In 1999, the Park Service reinstated this
policy, banning snowmobiles first on a temporary and later on a permanent basis.11 Litigation
regarding access to Denali was initiated by snowmobile user groups, but was withdrawn in June
2001, on the assumption that legislation would be introduced to address the issue. Legislation
(H.R. 4677 / S. 2589, 107th Congress) was introduced in the spring of 2002 that would have
allowed access to some portions of the old Park, while continuing the ban elsewhere. No action
was taken on these bills, however, and similar legislation has not been introduced in subsequent
years.
In January 2006, the National Park Service published a Final Backcountry Management Plan for
Denali National Park and Preserve. The plan notes that as a result of technology improvements
that have extended the range of snowmobiles, the use of such machines is now widespread in the
southern park additions and “growing rapidly.” “... [C]onflicts with other users, especially nonmotorized winter recreationists and subsistence users, are increasing, and concerns have been
raised about the effects of snowmachine use on wildlife, vegetation, water quality, air quality,
natural soundscapes, and other park resources.” Despite raising these issues, the plan concludes,
“There are currently few guidelines for managing use.”12

(...continued)
Escalating Snowmobile Use in the National Park System,” Press Release, April 27, 2000, p. 2. In addition to Alaska
parks and the three Yellowstone area units discussed below, Voyageurs National Park in Minnesota was also exempted
because of the express authorization of snowmobiles in its enabling legislation.
10
Statement of Denis P. Galvin, Deputy Director, National Park Service, before the Subcommittee on National Parks
and Public Lands, House Committee on Resources, Oversight Hearing on General Issues Involving Access to National
Parks, July 20, 2000, p. 2.
11
The temporary closure was instituted on February 3, 1999. The permanent closure was finalized June 19, 2000, at 65
Federal Register 37863.
12
Denali National Park and Preserve, National Park Service, U.S. Department of the Interior, Denali National Park and
Preserve Final Backcountry Management Plan, January 2006, p. 6 at http://www.nps.gov/dena/parkmgmt/
backcountryplan.htm.

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The other exception to the National Park Service’s general policy was the Yellowstone/Grand
Teton National Park area. The NPS had been sued in May 1997 by groups who alleged that the
Service was violating the National Environmental Policy Act, the Endangered Species Act, the
National Park Service Organic Act, and the Yellowstone Act in allowing use of snowmobiles in
the two parks and on the Rockefeller Memorial Parkway (which links them). The lawsuit was
settled within months when the NPS agreed to conduct an Environmental Impact Study (EIS) of
winter use of the parks. Upon completion of the study, the Clinton Administration promulgated a
final rule in January 2001, banning snowmobiles from Yellowstone, Grand Teton, and the
Rockefeller Parkway beginning in the winter of 2003-2004, but allowing continued visitor access
through the use of “snowcoaches”—guided tour-vans that run on rubber treads.13
Snowmobile manufacturers, represented by the International Snowmobile Manufacturers
Association (ISMA), have suggested that “cleaner, quieter” snowmobiles—a phrase not initially
defined—be allowed continued access to the parks. Their suggestion found a receptive audience
in the Bush Administration. On June 29, 2001, the Administration responded to a suit filed by
ISMA and the State of Wyoming by agreeing to reopen the decision to ban the vehicles from the
three Yellowstone area units. The Park Service agreed to prepare a Supplemental EIS and reach a
new Record of Decision by November 15, 2002 (a deadline subsequently extended to March 15,
2003).
The Record of Decision was signed March 25, 2003, and a final rule implementing it was
promulgated December 11, 2003.14 Despite receiving 104,802 comments on the final proposal,
91% of which “believed the proposed regulation does not adequately protect park resources due
to the presence of snowmobiles,”15 the Park Service reversed the ban in favor of daily limits on
entrants, emission standards for the snowmobiles, other access requirements, and an “adaptive
management strategy,” allowing park managers to take remedial action if monitoring indicates
unacceptable impacts from implementation. In explaining its position, the NPS stated: “We are
trying to provide a range of appropriate activities in the parks, while protecting park resources
and values.”16
The 2003 rule would have set a daily limit of 950 snowmobile entrance passes for Yellowstone
Park, 115 in Grand Teton National Park, and 400 on Rockefeller Memorial Parkway.17 On most
days, this limit would result in no reduction of snowmobile users; but on weekends and holidays,
when as many as 1,700 snowmobiles have entered the three park units, it could limit the number
of entrants. Snowmobile users would generally have been required to be accompanied by trained
guides (although the regulations would have allowed group members to be as much as 1/3 of a
mile from the guide, and the rule preamble conceded, given the noise of a snowmobile, that
communication is difficult if not impossible even between passengers on the same machine). To
discourage irresponsible behavior, alcohol use by snowmobile users would have been strictly
limited.
13

Special Regulations, Areas of the National Park System, 66 Federal Register 7260, January 22, 2001.
Special Regulations, Areas of the National Park System, 68 Federal Register 69268, December 11, 2003.
15
Ibid., p. 69269.
16
Ibid.
17
Seventy-five of the passes would have been for the Continental Divide Snowmobile Trail, which lies in both Grand
Teton National Park and the Parkway. These are counted in each unit’s total.
14

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The machines themselves would have been required to achieve a 90% reduction in hydrocarbon
emissions and a 70% reduction in carbon monoxide under the 2003 rules. Noise emissions would
have been limited to 73 dB(A), which the NPS estimates is about a 50% reduction compared to
conventional snowmobiles. To implement these provisions, the Yellowstone Park Superintendent
released a list of 10 snowmobile models approved for use during the 2003-2004 winter season, on
September 16, 2003. This list has been updated annually. The most recent version, released in
February 2008, contains 26 models.18
A hearing on the 2003 rules was held in the U.S. District Court for the District of Columbia on
December 15, 2003. The rules were vacated and remanded to the National Park Service by Judge
Emmett Sullivan on December 16. The judge held that there was no evidence in the record to
support the Bush Administration reversal of the previous agency position and that the decision,
therefore, was “arbitrary and capricious.” The court also held that the Supplemental EIS
accompanying the changes was “flatly inadequate” under NEPA and that the snowmobile
decision was “completely politically driven and result oriented.”19 The judge also ordered NPS to
respond to Bluewater Network’s 1999 rulemaking petition (seeking a ban on snowmobiles in all
National Park System units) by February 17, 2004.20 Judge Sullivan’s decision reinstated the
Clinton Administration rule and cut the number of snowmobiles entering the three Yellowstone
area park units in half for the 2003-2004 winter season in preparation for a complete ban in 20045.
Both ISMA and the State of Wyoming appealed the court’s ruling. Their request for a stay of the
Clinton-era rules pending resolution of their appeal was denied by Judge Sullivan in late
December 2003 and by a three-judge panel of the Court of Appeals January 13, 2004. Meanwhile,
however, the same groups petitioned the Federal District Court for Wyoming to overturn the
Clinton-era rules. That court responded February 10, 2004, when Judge Clarence Brimmer issued
a temporary restraining order against the Clinton rules and ordered the National Park Service to
develop temporary rules for the remainder of the 2004 winter season. The next day, the Park
Service issued such rules, allowing 780 snowmobiles to enter Yellowstone Park each day, an
increase of 287 machines. Grand Teton Park and the Rockefeller Parkway were allowed 140
snowmobiles, an increase of 90. An appeal of Judge Brimmer’s order was denied by the 10th
Circuit Court in Denver on March 10. (The Wyoming court vacated and remanded the Clinton
rules on October 14, 2004.)
As a result of the court decisions, snowmobile use in the three parks was substantially reduced
during the 2003-2004 winter season. According to NPS, an average of 258 snowmobiles entered
Yellowstone in January and February 2004, a reduction of two-thirds from the historic average. In
Grand Teton and the Rockefeller Parkway, the reduction was almost total: through February 10,
18

http://www.nps.gov/yell/parkmgmt/current_batlist.htm.
Fund for Animals v. Norton, 2003 U.S. Dist. LEXIS 22557 (D. D.C. December 16, 2003).
20
NPS denied the petition February 17, 2004, stating that given the differences among parks, “a service-wide directive
to prohibit all forms of recreational snowmobile use in the National Park System is no longer warranted and ... with
requirements for monitoring and increased use of newer technology snowmobiles, recreational uses can continue to be
a part of the NPS winter experience. This will allow decisions to be made on a park-by-park basis, relying on the
professional judgment of each park’s staff. They will be able to consider the lessons from Yellowstone, such as the use
of Best Available Technology requirements, guiding requirements, and adaptive management, as well as overall
technological improvements and any other new information, and will then be able to determine whether any review or
revision of their special regulations is needed.” See “Snowmobile Use in the National Park System,” Memorandum
from Assistant Secretary for Fish and Wildlife and Parks to the Director, National Park Service, February 17, 2004, pp.
4-5.
19

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only about 5 snowmobiles a day entered the two parks. After the February 10 court decision, this
number increased to about 20.21
The NPS subsequently issued Temporary Winter Use Plans for the 2004-2005, 2005-2006, 20062007, and 2007-2008 winter seasons.22 The temporary plans, which were intended to guide access
policy while additional studies were performed leading to a more permanent solution, allow 720
snowmobiles per day in Yellowstone, all commercially guided, and 140 snowmobiles in Grand
Teton National Park and the John D. Rockefeller, Jr., Memorial Parkway. With minor exceptions,
all of the snowmobiles are required to meet NPS best available technology (BAT) requirements
shown below in Table 2.23 Snowcoaches are also allowed. NPS concluded that the combination of
snowmobiles and snowcoaches “should provide a viable program for winter access to the parks,
and ... the opportunity for achieving historic visitor use levels.”24 The plans also include the
prohibition on alcohol use by snowmobilers that the Park Service had promulgated in its
remanded 2003 rule.
Despite the temporary plans’ allowable limits, snowmobile visits continued at levels far lower
than in the previous decade in the 2004-2008 winter seasons (Table 1). At 31,420, the number of
snowmobiles entering Yellowstone in 2007-2008 was 64% below the peak in 2001-2002, and was
less than half of the permitted number.25 The other two area units (Grand Teton National Park and
the Rockefeller Memorial Parkway) have seen even steeper declines. Grand Teton fell to 149
snowmobile visitors in the entire winter of 2004-2005, rising only to 799 in 2007-2008, compared
to its peak of 4,800 in 1999-2000. The Continental Divide Snowmobile Trail hosted only 11
snowmobiles last winter, compared to a peak of 2,006 in 2001-2002. The Rockefeller Parkway
saw more activity than Grand Teton, but still a marked decrease compared to earlier years: 7,351
snowmobile visitors in 2004-2005, rising to 11,695 in 2007-2008, compared to a peak of 31,011
in 2000-2001.26

21
Yellowstone National Park, “Winter Use Plans Environmental Assessment and Proposed Rule,” December 6, 2004,
p. 2 at http://www.nps.gov/yell/planvisit/winteruse/.
22
Department of the Interior, National Park Service, “Special Regulations; Areas of the National Park System; Final
Rule,” 69 Federal Register 65347, November 10, 2004. Hereafter, “November 2004 Regulations.” In anticipation of
any further developments in either the Wyoming or D.C. court cases, Congress enacted Section 146 of Title I of
Division E of the Consolidated Appropriations Act, 2005 (P.L. 108-447, H.R. 4818, H.Rept. 108-792), providing that
the Temporary Winter Use Rules described above “shall be in force and effect for the winter use season of 2004-2005.”
Similar language was approved for the 2005-2006 season in P.L. 109-54, the 2006-2007 season in P.L. 110-5, and was
contained in the reported Senate version of the 2008 appropriation (S. 1696, Section 116, S.Rept. 110-91), although not
enacted in the final Consolidated Appropriations Act (P.L. 110-161).
23
The exceptions are primarily for snowmobiles accessing other public lands or private property by way of specific
road or trail segments. See November 2004 Regulations, p. 65351.
24
November 2004 Regulations, p. 65350.
25
Winter Use Plans, Final Environmental Impact Statement, Yellowstone and Grand Teton National Parks, John D.
Rockefeller, Jr. Memorial Parkway, 2007, Volume 1, p. 154, at http://www.nps.gov/yell/parkmgmt/upload/
vol1_chapters1-3.pdf.
26
Ibid., p. 161. 2007-2008 data were obtained from the Yellowstone Park Superintendent’s Office.

˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ

Ŝȱ

—˜ –˜‹’•ŽœDZȱ—Ÿ’›˜—–Ž—Š•ȱŠ—Š›œȱŠ—ȱŒŒŽœœȱ˜ȱŠ’˜—Š•ȱŠ›”œȱ

ȱ

Table 1. Snowmobile Visits to Yellowstone Area Park Units
Mem. Pkwy.

Rockefeller

Cont. Divide
Snowmobile Trail

3,421

26,401

2,006

0,406

2,305

23,062

1,752

2003-2004

30,437

1,939

9,217

139

2004-2005

24,049

149

7,351

11

2005-2006

28,833

268

10,161

17

2006-2007

31,805

287

11,710

14

2007-2008

31,420

799

11,695

11

Yellowstone

Grand Teton

Nat’l Park

Nat’l Park

2001-2002

87,206

2002-2003

Year

Sources: National Park Service, Winter Use Plans, Final Environmental Impact Statement, Yellowstone and

Grand Teton National Parks, John D. Rockefeller, Jr. Memorial Parkway, 2007, for years 2001-2007; NPS Stats
for 2007-2008. Although the Rockefeller Memorial Parkway is 27 miles long, virtually all the snowmobiles using it
originate at Flagg Ranch, a resort located 2 miles from the south entrance of Yellowstone Park, whence they
travel to the Yellowstone Park South entrance. As a result, they are counted in the totals for Yellowstone Park
as well as under the Parkway heading.
One result of the declining snowmobile use was a marked increase in visitors using other modes
of travel. Snowcoach visitors to Yellowstone increased to 22,344 in 2007-2008, up 89%
compared to the peak snowmobile year. In Grand Teton, the number of cross country skiers more
than doubled (to 13,003) compared to the number in the peak snowmobile year.

˜ŸŽ–‹Ž›ȱŘŖŖŝȱ’—Ž›ȱœŽȱ•Š—ȱ
The Park Service also began additional studies to develop a final winter use plan in 2004, and on
November 20, 2007, it finalized the fruits of its effort by issuing a Record of Decision.27 Termed a
“Winter Use Plans/Final Environmental Impact Statement,” this latest plan evaluated seven
alternatives. It presented additional data on the effects of snowmobiles and snowcoaches on air
quality, noise, and wildlife, and evaluated the economic impacts on surrounding communities of
restricting snowmobile access to the three Yellowstone area NPS units.
The new plan set final rules and access limits somewhat more stringent than those that have been
in place during the past four winter seasons, but significantly higher than actual use during that
period. It would allow 540 snowmobiles per day access to Yellowstone, and a combined 65 in
Grand Teton National Park and the Rockefeller Memorial Parkway. The snowmobiles would be
required to meet best available technology requirements for emissions and noise, and it would
require that snowmobilers be accompanied by commercial guides. It would also authorize entry to
83 snowcoaches per day.28

27
Record of Decision, “Winter Use Plans/Final Environmental Impact Statement,” is at http://parkplanning.nps.gov/
document.cfm?parkID=111&projectId=12047&documentID=21206. Hereafter referred to as the ROD.
28
National Park Service, Winter Use Plans, Final Environmental Impact Statement, Yellowstone and Grand Teton
National Parks, John D. Rockefeller, Jr. Memorial Parkway, 2007, Abstract, at http://www.nps.gov/yell/parkmgmt/
winterusetechnicaldocuments.htm.

˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ

ŝȱ

—˜ –˜‹’•ŽœDZȱ—Ÿ’›˜—–Ž—Š•ȱŠ—Š›œȱŠ—ȱŒŒŽœœȱ˜ȱŠ’˜—Š•ȱŠ›”œȱ

ȱ

On September 15, 2008, Judge Emmett Sullivan of the U.S. District Court for the District of
Columbia vacated the plan, finding it “arbitrary and capricious, unsupported by the record, and
contrary to law.”29 The judge found:
According to NPS’s own data, the WUP [Winter Use Plan] will increase air pollution,
exceed the use levels recommended by NPS biologists to protect wildlife, and cause major
adverse impacts to the natural soundscape in Yellowstone. Despite this NPS found that the
plan’s impacts are wholly “acceptable,” and utterly fails to explain this incongruous
conclusion.30

With the rule vacated, it is unclear what limits will apply in the coming winter season. On
October 1, 2008, NPS announced that it would propose a new temporary Winter Use Plan that
would be ready for public comment in early November and would be in place before the
December 15 scheduled opening of the winter season.31

•ŽŠ—ȱ’›ȱŒȱŠ—ȱ˜’œŽȱ˜—›˜•ȱŒȱŽž•Š’˜—ȱ
In reversing the Clinton Administration rules on Yellowstone access, the National Park Service
set limits on emissions and noise from the snowmobiles that would be allowed in the three
Yellowstone area park units. Simultaneously, the Environmental Protection Agency developed
emission limits applicable to new snowmobiles offered for sale anywhere in the United States
beginning in 2006 and 2007. The following sections of this report describe the EPA regulations
and look at the broader issue of snowmobile emissions.
The Clean Air Act gives EPA authority to regulate emissions from mobile sources of pollution,
including off-road sources such as snowmobiles; but until 2006, snowmobiles (with the exception
of those entering the Yellowstone area national parks) were not subject to any federal or state
emission regulations. Nor, with the exception of those allowed in Yellowstone since 2004, have
they ever been subject to noise regulations. EPA has authority under Section 6 of the Noise
Control Act of 1972 to regulate noise from “transportation equipment (including recreational
vehicles and related equipment).” But the Agency’s Office of Noise Abatement and Control was
disbanded in 1982, and EPA has not issued any regulations under the statute in the 26 years since
then.

—˜ –˜‹’•Žȱ–’œœ’˜—œȱ
Snowmobiles generally run on two-stroke engines—the type of engine that traditionally has
powered outboard motors and lawnmowers. In a two-stroke engine, fuel enters the combustion
chamber at the same time that exhaust gases are expelled from it. As a result, as much as onethird of the fuel passes through the engine without being combusted.32 This causes poor fuel
economy and high levels of emissions, particularly hydrocarbons and carbon monoxide.
29

Greater Yellowstone Coalition v. Department of the Interior, D.D.C., No. 07-CV-2111, 9/15/08; National Parks
Conservation Ass’n v. Department of the Interior, D.D.C., No. 07-CV-2112, 9/15/08, p. 61.
30
Ibid., p. 62.
31
National Park Service, “Yellowstone and Grand Teton to Consider Options on New Temporary Winter Use Plan,”
Press Release, October 1, 2008, at http://www.nps.gov/yell/parknews/08084.htm.
32
In a four-stroke engine (used in automobiles and some newer outboard motors and lawn mowers, but not generally
(continued...)

˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ

Şȱ

ȱ

—˜ –˜‹’•ŽœDZȱ—Ÿ’›˜—–Ž—Š•ȱŠ—Š›œȱŠ—ȱŒŒŽœœȱ˜ȱŠ’˜—Š•ȱŠ›”œȱ

In one hour, a typical snowmobile emits as much hydrocarbon as a 2008 model automobile emits
in 54,000 miles of driving.33 In a day of use, a snowmobile may emit as much hydrocarbon as an
automobile emits over its entire lifetime. The hydrocarbons (gasoline) emitted by snowmobiles
(or other mobile sources, for that matter) are of concern because they contain benzene,
formaldehyde, and at least three other substances that are known or suspected human
carcinogens.
Snowmobiles meeting EPA regulations also emit as much carbon monoxide (CO) in an hour as a
2008 model auto does in 1,050 miles of driving. Carbon monoxide is a poisonous gas that, at low
levels, can affect those who suffer from cardiovascular disease, such as angina. The impact of CO
emissions on ambient air quality is of at least equal concern as that of hydrocarbons because of
the tendency for atmospheric accumulation of CO in winter.
In preparing the 2000 Environmental Impact Statement for the decision on snowmobile access to
Yellowstone, the National Park Service measured emissions from snowmobiles and compared
them to other emission sources in the park. The Service also estimated the concentrations
(ambient levels) of carbon monoxide (CO) and particulate matter (PM) present in the air and
compared these concentrations to air quality standards. The EIS concluded that the 8-hour
maximum concentration of carbon monoxide at the West Yellowstone entrance to the park
exceeded the National Ambient Air Quality Standard for CO by nearly 70% (a concentration of
15.15 parts per million vs. the standard of 9).34 The analysis also concluded that snowmobiles
accounted for 97.9% of the CO at West Yellowstone during winter months.
Noise has also been an issue. Opponents of allowing snowmobiles in Yellowstone and other units
of the national park system argue that the parks are special places whose remoteness, beauty, and
quiet inspire reflection and awe. The noise of engines is incompatible with this atmosphere, they
argue. As the National Park Service itself states in its Record of Decision, “Snowmobile use, in
historical numbers, is inconsistent with winter park landscapes that uniquely embody solitude,
quiet, undisturbed wildlife, ... and the enjoyment of these resources by those engaged in nonmotorized activities.”35
Snowmobile enthusiasts counter that the parks cover vast areas and that snowmobiles are
restricted to a few roads—the same roads traversed by cars, recreational vehicles, and buses in
summer. They also assert that snowmobile use is compatible with the NPS responsibility to
promote visitor use and enjoyment of park resources. Park Service studies indicate that the sound
of snowmobiles can be heard for significantly greater distances than that of automobiles,
however, and in the late 1990s was essentially continuous during the winter at key locations in
(...continued)
used in snowmobiles) the combustion chamber takes in fuel, compresses it, ignites it, and exhausts it in separate cycles,
leading to far more complete combustion and lower emissions, even without the application of emission controls.
33
EPA provided a similar comparison for 2001 model automobiles and uncontrolled snowmobiles in U.S. EPA, Office
of Air and Radiation, Draft Regulatory Support Document: Control of Emissions from Unregulated Nonroad Engines,
September 2001, p. I-25, available at http://www.epa.gov/otaq/regs/nonroad/proposal/cleanrec.htm#rsd. CRS updated
this information to reflect 2007 snowmobile emission standards and Tier 2 auto emissions requirements.
34
U.S. Department of the Interior, National Park Service, Winter Use Plans, Final Environmental Impact Statement for
the Yellowstone and Grand Teton National Parks and John D. Rockefeller, Jr., Memorial Parkway, Volume 1, Chapter
4, p. 224, available at http://www.planning.nps.gov/document/yellwinterusevol1.pdf. Ambient air quality standards
were not exceeded elsewhere in the park.
35
ROD, p. 4.

˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ

şȱ

—˜ –˜‹’•ŽœDZȱ—Ÿ’›˜—–Ž—Š•ȱŠ—Š›œȱŠ—ȱŒŒŽœœȱ˜ȱŠ’˜—Š•ȱŠ›”œȱ

ȱ

Yellowstone: snowmobile noise could be heard 95% of the time by visitors at Old Faithful and
87% of the time at the Grand Canyon of the Yellowstone, according to NPS’s December 2000
Federal Register notice.36

ȂœȱŘŖŖŘȱŽž•Š’˜—œȱ
Regulations for snowmobile and other non-road engine emissions were signed by the EPA
Administrator September 13, 2002 and appeared in the Federal Register November 8, 2002.37 As
shown in Table 2, the regulations require reduction of both carbon monoxide and hydrocarbon
emissions from new snowmobiles by a little more than 30% starting in 2006 and by an average of
50% by 2012, with an intermediate step in 2010. (The regulations did not require any controls on
snowmobiles sold before 2006.) For comparison, Table 2 also shows the Yellowstone-specific
standards that have been imposed by the National Park Service.
According to EPA, the 2006/2007 reductions can be achieved without major changes in
technology, in part because they apply to the average of a manufacturer’s fleet emissions, rather
than to individual machines. This allows manufacturers to provide a range of models, some with
advanced emission controls and others without: “While some advanced technologies such as twostroke direct injection and four-stroke engines, would be found in some models, many models
would still be equipped with two-stroke engines with relatively minor engine modifications
resulting in minimum emission reductions, while some models may not even have any emission
controls.”38 EPA estimates the cost of these Phase 1 controls at $73 per snowmobile. Vehicles
meeting the standards will be more fuel-efficient, resulting in an average reduction in operating
cost of $57, thus offsetting most of the initial cost increase.

Table 2. EPA and NPS Snowmobile Emission Limits
Year

Carbon Monoxide (CO)

% Reduction

Hydrocarbons (HC)

% Reduction

pre-control average

397 g/kW-hr

2006/2007a

275 g/kW-hr

30.7%

100 g/kW-hr

33.3%

2010

275 g/kW-hr

30.7%

75 g/kW-hr

50%

2012b

200 g/kW-hra

49.6%

75 g/kW-hra

50%

Yellowstone/

120 g/kW-hr

70%

15 g/kW-hr

90%

150 g/kW-hr

2003 (NPS)

36

National Park Service, Proposed Rule, Special Regulations, Areas of the National Park System, 65 Federal Register
79026, December 18, 2000.
37
U.S. EPA, Control of Emissions from Nonroad Large Spark-Ignition Engines, and Recreational Engines (Marine and
Land-Based), Final Rule, 67 Federal Register 68241, available at http://www.epa.gov/fedrgstr/EPA-AIR/2002/
November/Day-08/a23801.htm.
38
Notice of Proposed Rulemaking: Control of Emissions from Nonroad Large Spark Ignition Engines and Recreational
Engines (Marine and Land-based), Preamble, 66 Federal Register 51154, October 5, 2001. Further discussion,
including the cost estimates, is found on pp. 51169-51170. The preamble to the final standards says that one scenario
for meeting the 2006/2007 standards would be 15% four-stroke engines, 15% direct injection two-strokes, 60%
conventional two-strokes with improved carburetion, enleanment strategies, and engine modifications; presumably, the
other 10% would have no modifications at all. Control of Emissions from Nonroad Large Spark-ignition Engines, and
Recreational Engines (Marine and Land-based), Final Rule, as signed September 13, 2002, Preamble, p. 93, available at
http://www.epa.gov/otaq/regs/nonroad/2002/preamble.pdf.

˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ

ŗŖȱ

—˜ –˜‹’•ŽœDZȱ—Ÿ’›˜—–Ž—Š•ȱŠ—Š›œȱŠ—ȱŒŒŽœœȱ˜ȱŠ’˜—Š•ȱŠ›”œȱ

ȱ

g/kW-hr = grams per kilowatt-hour.
a. Half of snowmobiles sold in 2006 must comply with the EPA standards. With a few exceptions, all
snowmobiles sold in 2007 must comply.
b. EPA’s 2012 standards allow manufacturers to trade additional reductions in HC for increases in CO
emissions, provided that CO emissions are reduced at least 30%, HC emissions are reduced at least 50%,
and the total of HC+CO emissions sums to 100%. Thus, for example, HC reductions of 60% and CO
reductions of 40% would satisfy the requirement, as would HC reductions of 70% and CO reductions of
30%.
Note:

The 2010 and 2012 standards, which also are fleet averages, can also be met without eliminating
two-stroke engines, according to the Agency. Because two-stroke engines produce more power
than similar size four-strokes and are easy to start in cold weather, the Agency expects the
industry to continue to manufacture mostly two-stroke engines even in 2012, although many
would be modified with direct injection technology to reduce emissions. According to the
Agency, “A potential scenario for meeting these standards could be a mixture of 50 percent direct
injection, 20 percent four-stroke engines, and 30 percent with engine modifications.”39 The cost
of these changes would average an additional $131 per snowmobile in 2010, according to EPA,
but the costs would be offset by $286 in fuel savings and improved performance, so that lifetime
costs would actually be $155 lower. The same is true of the 2012 standards: the added cost of $89
per snowmobile is offset by $191 in fuel savings and improved performance, according to EPA,
for a net savings of $102 per vehicle.40
The costs of each of the three phases are incremental. Thus, when fully implemented, the
standards would cost an additional $293 per snowmobile, according to the Agency; lifetime
operating costs, however, would decline by $534. Combining these two factors, the standards
would decrease total costs by $241 per snowmobile when fully implemented.
The standards do not include noise limits. While acknowledging that the Agency has the authority
to set noise standards, the proposal stated that “at this time we do not have funding to pursue
noise standards for nonroad equipment that does not have an existing noise requirement.”41 An
Agency source confirmed that the proposed standards would have essentially no impact on
noise.42 Despite receiving comments from a number of organizations that the standards should
address noise, the Agency restated in its response to public comments that it would not address
the issue, adding that Congress would need to provide appropriations for the Agency to begin any
noise control initiative.43
As noted, the National Park Service promulgated noise standards applicable to snowmobiles
entering its three Yellowstone area park units beginning December 17, 2003, under the winter use
rule that was vacated; it restated these standards in its Temporary Winter Use Plan that took effect
in 2004.44 According to Park Service estimates, these standards would require a reduction of

39

Preamble to the Final Rule, ibid., p. 94.
Ibid., Table IX.B-1, p. 179.
41
Ibid., p. 135.
42
Personal communication, John Mueller, U.S. EPA Office of Transportation and Air Quality, September 28, 2001.
43
U.S. EPA, Office of Air and Radiation, Summary and Analysis of Comments: Control of Emissions from
Unregulated Nonroad Engines, September 2002, p.II-78, available at http://www.epa.gov/otaq/regs/nonroad/2002/
r02023.pdf.
44
36 CFR 7.13(a)(6)(C)(ii), November 2004 Regulations, p. 65361.
40

˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ

ŗŗȱ

ȱ

—˜ –˜‹’•ŽœDZȱ—Ÿ’›˜—–Ž—Š•ȱŠ—Š›œȱŠ—ȱŒŒŽœœȱ˜ȱŠ’˜—Š•ȱŠ›”œȱ

about 50% in noise emitted by the affected snowmobiles, compared to conventional uncontrolled
snowmobiles.45

ŽŠŒ’˜—ȱ˜ȱ‘ŽȱȱŠ—Š›œȱ
Both the snowmobile industry and environmentalists challenged EPA’s standards in court. On
June 1, 2004, the U.S. Court of Appeals for the D.C. Circuit vacated the standard for nitrogen
oxides and remanded the 2012 standards for hydrocarbons and carbon monoxide. The court
directed EPA “to clarify (1) the statutory and evidentiary basis of the Agency’s assumption that
the standards must be sufficiently lenient to permit the continued production of all existing
snowmobile models, and (2) the analysis and evidence underlying the Agency’s conclusion that
advanced technologies can be applied to no more than 70% of new snowmobiles by 2012.”46 EPA
has not yet responded to the remand, and does not expect to do so until 2010 at the earliest.47
The International Snowmobile Manufacturers Association (ISMA) has argued that EPA grossly
underestimated the costs of compliance, and that the standards will lead to the elimination of
entry-level snowmobiles from the market. Cleaner, quieter machines can be made, according to
ISMA, but they cost more, are heavier, and can only be ridden on groomed roads. ISMA has
estimated that the cleanest four-stroke engines cost an additional $1,700 (about 30% more than
average prices). Even modest improvements to two-stroke engines will cost $350-$400 per
machine, according to the Association.48
Bluewater Network, on the other hand—the environmental group most identified with
snowmobile issues—feels the rules should be much stronger.49 In comments submitted to EPA,
Bluewater encouraged the Agency to set standards “that can only be met using the best available
technology, which we believe to be four-stroke engines with particle traps and three-way
catalysts.”50 They also want mandatory emission labels for the machines, and are disappointed
that the Agency chose not to set noise standards.
Bluewater has pointed to the Clean Snowmobile Challenge, an annual design contest open to
college engineering students and sponsored by the Society of Automotive Engineers, as
demonstrating that machines far cleaner than EPA’s standards are feasible. The winning entry in
the 2001 Challenge reduced CO 78.8% and unburned hydrocarbons 97.6% and significantly
45

Although a 73-decibel snowmobile would be quieter, it did not satisfy the judge in the Yellowstone Winter Use Plan
case. Citing the Winter Use Plan itself, Judge Sullivan concluded that a sound measuring 70 decibels is perceived to be
noisy—”the equivalent of being in a room with a running vacuum cleaner.” He found that the model used to estimate
the percent of time that noise would be audible in the park underestimated the sound level when compared to actual
field measurements, and that it failed to account for temperature inversions, which are common in Yellowstone, and
which cause sound to travel much farther. He found that the Park Service used park-wide audibility in order to obscure
the impacts in areas frequented by visitors. And he cited NPS itself as admitting that the “percent time audible impact
will be ‘major and adverse.’” September 15, 2008 opinion, previously cited, pp. 26-41.
46
Bluewater Network v. EPA, D.D.C., No. 03-1003, June 1, 2004, p. 4.
47
Personal communication, EPA Office of Transportation and Air Quality, November 2, 2007.
48
Personal communication, Ed Klim, President, ISMA, September 27, 2001.
49
Personal communication, Sean Smith, Bluewater Network, September 27, 2001. Also see “Bush Administration Fails
to Protect Public Health, Folds to Industry Interests,” Press Release, September 13, 2002, available at
http://www.bluewaternetwork.org/press_releases/pr2002sep13_pl_eparule.pdf.
50
Bluewater Network, “Comments on the Environmental Protection Agency’s Advanced Notice of Proposed
Rulemaking, Docket A-2000-01,” p. 2.

˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ

ŗŘȱ

ȱ

—˜ –˜‹’•ŽœDZȱ—Ÿ’›˜—–Ž—Š•ȱŠ—Š›œȱŠ—ȱŒŒŽœœȱ˜ȱŠ’˜—Š•ȱŠ›”œȱ

reduced noise, at a cost of $600.51 In the 2006 contest, the winning entry reduced CO emissions
83% and unburned hydrocarbons more than 99% at a cost of $314.52 “If college students are able
to build cleaner and quieter machines, surely the billion-dollar snowmobile industry can do as
well,” said Bluewater Public Land Director Sean Smith.53
Both Bluewater and the snowmobile manufacturers argue that EPA has misinterpreted the legal
authority on which the new standards rely. Bluewater (as well as other environmental groups and
the National Association of Clean Air Agencies (formerly STAPPA), the association representing
state air pollution program administrators, argue that EPA has promulgated standards that are less
stringent than the law requires. Section 213(a)(3) of the Clean Air Act requires the Agency to
promulgate standards that “achieve the greatest degree of emission reduction achievable ... giving
appropriate consideration to the cost ... and to noise, energy, and safety factors....” Four-stroke
engine technology, achieving greater emission reductions than the Agency promulgated, is
already available, they note—machines using this technology are on the market. Cost, noise, and
energy factors cannot be used as arguments against adoption of this technology: the lifetime cost
of such engines would be lower than that of current engines, according to the Agency’s own
analysis; the technology uses far less energy, and could be substantially quieter than current
engines. Thus, according to these groups, the Agency’s standards do not meet the requirements of
the act.
Snowmobile and other nonroad-vehicle manufacturers, on the other hand, focus on Section
213(a)(2) of the act, which ties the Agency’s authority to regulate nonroad engines to a finding by
the Administrator that emissions from such engines or vehicles “are significant contributors to
ozone or carbon monoxide concentrations in more than 1 area which has failed to attain the
national ambient air quality standards for ozone or carbon monoxide.” EPA addressed this issue
before beginning the process of developing regulations: on June 17, 1994, the Agency made an
affirmative determination that emissions from nonroad engines and vehicles are significant
contributors to ozone, CO, and particulate matter in more than one nonattainment area.54 On
December 7, 2000, the Agency issued a finding that recreational vehicles (including
snowmobiles) are among the specific categories of nonroad vehicles that contribute to such
pollution.55 In its October 5, 2001 Federal Register notice, which proposed the snowmobile
standards, the Agency identified 7 areas in Alaska, Washington, Colorado, Oregon, and Montana
that have significant populations of snowmobiles and have failed to attain the air quality standard
for CO.56

51

See “‘Clean’ Snowmobile Produces Lower Emissions than the Average Car at SAE Clean Snowmobile Challenge
2001,” Press Release, April 10, 2001.
52
The 2006 Clean Snowmobile Challenge results can be found at http://www.mtukrc.org/snowmobile.htm, with
emissions data at http://www.mtukrc.org/download/score_sheet_sae_fuel_csc2006.xls. To derive the percentage
reductions, we compared the emissions of CO and unburned hydrocarbons to the “uncontrolled average” data in this
report’s Table 1.
53
Personal communication, Sean Smith, Bluewater Network, September 27, 2001.
54
59 Federal Register 31306, June 17, 1994.
55
65 Federal Register 76790, December 7, 2000.
56
66 Federal Register 51105-51107, October 5, 2001. The Preamble to the final rule revised the list of 7 areas,
identifying 6 nonattainment areas in which the Agency believes snowmobiles are significant contributors to CO
concentrations; the Agency added that there are 6 additional areas that have not been classified nonattainment, but
where air quality monitoring indicates a need for CO control. See Preamble to the Final Rule, previously cited, p. 18.

˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ

ŗřȱ

ȱ

—˜ –˜‹’•ŽœDZȱ—Ÿ’›˜—–Ž—Š•ȱŠ—Š›œȱŠ—ȱŒŒŽœœȱ˜ȱŠ’˜—Š•ȱŠ›”œȱ

Manufacturers of snowmobiles and other nonroad vehicles note, however, that carbon monoxide
concentrations have declined [chiefly as a result of auto emission standards] and that none of the
7 areas identified by the Agency has exceeded the CO standard in recent years, even if they were
still formally classified as nonattainment at the time of the proposal.57 CO nonattainment today is
essentially a problem in urban “hot spots,” according to manufacturers, and snowmobiles make
no contribution to that problem.58

Ž’œ•Š’ŸŽȱ œœžŽœȱ
Members of Congress, both from western and other states, have expressed an interest in whether
there will be continued snowmobile access to national parks. At least five hearings have been held
on these issues since the 106th Congress,59 and Congress has on three occasions approved
language in appropriations bills to require that NPS Temporary Winter Use Rules permitting
snowmobiles in Yellowstone and Grand Teton National Parks and on the Rockefeller Memorial
Parkway remain in effect for the year covered by the appropriations bill.60 The FY2008 Interior
appropriations bill (S. 1696, §116), as reported by the Senate Appropriations Committee (S.Rept.
110-91), would have continued this temporary solution, stipulating that Yellowstone’s interim
winter management rule remain in effect during the 2007-2008 winter season, but the final
Consolidated Appropriations Act (P.L. 110-161) did not include such language. Lawsuits
challenging the NPS Final Winter Use Plan did not request preliminary injunctions, however,
allowing local operations to continue under the same temporary rules that had been in effect for
the previous three years.
In the 108th Congress, Representative Holt twice attempted to amend Interior Department
Appropriation bills to prohibit spending to manage recreational snowmobile use in the three
Yellowstone area park units except in accordance with the Clinton Administration rule phasing
out snowmobiles. The first such amendment (H.Amdt. 266 to H.R. 2691) was defeated on a tie
vote, 210-210, July 17, 2003. The second attempt (H.Amdt. 563 to H.R. 4568) was defeated on
June 17, 2004, by a vote of 224-198. Other legislation to prohibit snowmobile access to national
parks and to grant continued access was introduced, but not acted on, in the 107th and 108th
Congresses.

˜—Œ•žœ’˜—œȱ
Snowmobile issues remain far from resolved, despite actions by Congress, EPA, the National
Park Service, and the courts. Congress and the NPS have provided a temporary resolution of the
Yellowstone access issue since 2004, but the issue is now returning to the limelight, as a federal
district court has vacated final regulations for Yellowstone access for a third time. The
57

None of the seven was still classified nonattainment in 2007.
Statement of Ed Klim, President, ISMA, at EPA Public Hearing, Washington, DC, October 24, 2001.
59
The most recent hearing was before the House Resources Committee’s Subcommittee on National Parks, Oversight
Hearing on Snowmobile Use in the National Park System, April 12, 2005.
60
The most recent of these was the FY2007 Revised Continuing Appropriations Resolution (P.L. 110-5, § 20516) to
keep the NPS Yellowstone interim rule in effect throughout the 2006-2007 winter use season. For earlier years, see
Section 146 of Title I of Division E of the Consolidated Appropriations Act, 2005 (P.L. 108-447, H.Rept. 108-792) and
Section 126 of Department of the Interior, Environment, and Related Agencies Appropriations Act, 2006 (P.L. 109-54).
58

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ȱ

—˜ –˜‹’•ŽœDZȱ—Ÿ’›˜—–Ž—Š•ȱŠ—Š›œȱŠ—ȱŒŒŽœœȱ˜ȱŠ’˜—Š•ȱŠ›”œȱ

development of these rules showed that public interest in snowmobile issues remains significant,
and that the National Park Service’s preferred alternatives for snowmobile access to Yellowstone
remain overwhelmingly unpopular. The draft Yellowstone area Winter Use Plan that was open for
comment from March through June 2007 generated 122,190 public comments, of which only 193
(0.1%) supported the NPS preference.61 Among those opposed, environmental groups and
individuals that want snowmobiles banned from the park form a solid majority. They are joined
by 7 of the 8 living former directors of the National Park Service itself. The Environmental
Protection Agency was also critical of the spring 2007 preferred alternative, noting that it would
result in five times more carbon monoxide emissions and 17 times more hydrocarbon emissions
than the exclusive use of multi-passenger snowcoaches. EPA concluded that “either the preferred
alternative should be modified or a different alternative should be selected that meets the resource
protections identified by the National Park Service.”62
This level of opposition would seem to guarantee that Members of Congress will retain an
interest in the resolution of these issues. Continued action is also likely in the courts, as the
National Park Service responds to the latest court decision.

ž‘˜›ȱ˜—ŠŒȱ —˜›–Š’˜—ȱ
(name redacted)
Specialist in Environmental Policy
[redacted]@crs.loc.gov, 7-....

61

See National Park Service, Public Comment Report: Winter Use Plans, Draft Environmental Impact Statement,
Yellowstone and Grand Teton National Parks and John D. Rockefeller, Jr., Memorial Parkway, p. 4 at
http://www.nps.gov/yell/parkmgmt/upload/deis_results_draft2.pdf.
62
“EPA Raises Concerns About Latest Plan For Snowmobile Use in Yellowstone Park,” Daily Environment Report,
June 22, 2007, p. A-4. NPS did modify the preferred alternative subsequent to EPA’s comments. The number of
snowmobiles allowed in Yellowstone would be 540 under the November 2007 Record of Decision, rather than 720. It
is not clear whether this change is sufficient to earn EPA’s support.

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/crs%3ARL31149. Public record. Not legal advice.