Wilderness Act & National Wilderness Preservation System
The Wilderness Act of 1964 (16 U.S.C. §§ 1131–1136) created the National Wilderness Preservation System — a network of federally owned lands permanently protected in their natural, undeveloped condition "where the earth and its community of life are untrammeled by man, where man himself is a visitor who does not remain." The System now encompasses more than 111 million acres across 806 designated wilderness areas in 44 states and Puerto Rico, managed by four federal agencies: the Forest Service, National Park Service, Fish & Wildlife Service, and Bureau of Land Management. Within designated wilderness, Congress has prohibited roads, buildings, motor vehicles, motorized equipment, and commercial enterprises — preserving these areas as they existed before development, for recreation, solitude, and ecological preservation.
Current Law (2026)
| Parameter | Value |
|---|---|
| Governing law | 16 U.S.C. §§ 1131–1136 (Wilderness Act, 1964) |
| Total acreage | ~111 million acres (approximately 5% of U.S. land area) |
| Designated areas | 806 wilderness areas in 44 states and Puerto Rico |
| Managing agencies | USFS, NPS, FWS, BLM |
| Designation authority | Congress only — no executive or agency authority to designate wilderness |
| Prohibited uses | Roads, permanent structures, motor vehicles, motorized equipment, mechanical transport, commercial enterprise, timber harvest |
| Permitted uses | Hiking, camping, hunting, fishing, horseback riding, scientific research |
| Existing rights | Pre-existing mining claims, water rights, and grazing permits generally grandfathered |
| Minimum size | Generally 5,000+ acres, or sufficient size to make preservation practicable |
| State with most wilderness | Alaska (~57 million acres, including vast ANILCA designations) |
Legal Authority
- 16 U.S.C. § 1131 — National Wilderness Preservation System (establishes the System to secure an enduring resource of wilderness for the American people; defines wilderness as an area "where the earth and its community of life are untrammeled by man" that retains its primeval character, has no permanent improvements, and provides outstanding opportunities for solitude or primitive recreation)
- 16 U.S.C. § 1132 — Extent of system (existing Forest Service wilderness, wild, and canoe areas became the initial System; Secretary of Agriculture must review primitive areas for wilderness designation; Secretary of Interior must review roadless areas in national parks and wildlife refuges; recommendations go to Congress)
- 16 U.S.C. § 1133 — Use of wilderness areas (agencies must preserve wilderness character; prohibits commercial enterprise, permanent roads, motor vehicles, motorized equipment, mechanical transport, structures, and installations; allows exceptions for fire and insect control, established grazing, aircraft/motorboats where already established, mining subject to conditions, and water resource projects authorized by the President)
- 16 U.S.C. § 1134 — State and private lands within wilderness areas (owners of state or private land surrounded by wilderness must be given reasonable access; land exchanges authorized to consolidate ownership)
- 16 U.S.C. § 1136 — Annual reports to Congress (Secretaries of Agriculture and Interior must jointly report to Congress at each session on the status of wilderness study areas, recommendations for designation, and progress in administering the System — the primary accountability mechanism for tracking the designation pipeline)
How It Works
The Wilderness Act defines wilderness in terms both poetic and legally operational: an area "where the earth and its community of life are untrammeled by man, where man himself is a visitor who does not remain" (16 U.S.C. § 1131) — specifically, land primarily shaped by natural forces with human imprint substantially unnoticeable, offering outstanding opportunities for solitude or primitive recreation, at least 5,000 acres, and potentially containing ecological, geological, scientific, scenic, or historic value. Only Congress can designate wilderness — no president, cabinet secretary, or federal agency has unilateral authority (§ 1132), making designations permanent in a way that executive orders cannot match. Within designated areas, the Act broadly prohibits permanent roads, motor vehicles (including ATVs, snowmobiles, and mountain bikes, which courts have held constitute "mechanical transport"), motorized equipment, permanent structures, commercial enterprise, and commercial timber harvest (§ 1133).
Certain pre-existing uses survive designation: grazing permits established before designation generally continue subject to reasonable regulation (§ 1133(d)(4)), valid mining claims from before designation may still be developed under conditions protecting wilderness character, and aircraft and motorboats may continue where already established. The President may authorize water resource projects in wilderness if deemed in the national interest — authority exercised rarely. Fire management and insect or disease control are permitted as necessary to protect wilderness values. Lands under consideration for designation are managed as wilderness study areas (WSAs) under a "non-impairment" standard — meaning BLM and other agencies must preserve their wilderness character pending congressional action, and some WSAs have remained in this limbo for decades, neither formally designated nor released for development.
How It Affects You
If you're a hiker, backpacker, or backcountry hunter: Wilderness areas offer the most protected and primitive outdoor recreation available on public lands — no roads, no motors, minimal infrastructure, and in many areas, no cell service. Many popular wilderness areas require overnight permits to manage crowding: the John Muir Wilderness (California), Boundary Waters Canoe Area Wilderness (Minnesota), Zion Narrows, and the Grand Canyon Corridor all use quota systems. Permits for peak summer dates often sell out within minutes of the reservation window opening, typically 2-6 months in advance. Check specific area requirements through the managing agency's website — Forest Service areas at recreation.gov and NPS areas at nps.gov/permits. Day hiking in most wilderness areas is unrestricted, though Leave No Trace principles (lnt.org) apply. Pack out all waste, camp 200 feet from water and trails, and use a bear canister or hang food where required — rangers in popular wilderness areas actively enforce these rules with citations.
If you ride mountain bikes, ATVs, or snowmobiles: Wilderness areas are legally closed to all mechanical transport — a category that includes mountain bikes, ATVs, snowmobiles, e-bikes, and game carts with wheels. The prohibition comes directly from 16 U.S.C. § 1133 and has been consistently upheld in courts. This is not a discretionary management policy that rangers can waive — it's a statutory prohibition. If you're planning a mountain bike trip in the West, check whether the land is designated wilderness (using caltopo.com or gaia GPS, which display federal land designations) before leaving the trailhead. Nearby national forests and BLM lands outside wilderness designations often allow mountain bikes and motorized use; many trail systems are specifically designed for these uses. Legislative proposals to amend the Wilderness Act to allow mountain bikes have been introduced multiple times (most recently similar to HR 1065) but have not advanced.
If you're a rancher with grazing permits in a wilderness area: Livestock grazing that was established before a wilderness designation was generally grandfathered under 16 U.S.C. § 1133(d)(4), and permits continue subject to reasonable regulation. In practice, this means your existing permit typically survives designation, but the managing agency may impose additional conditions to protect wilderness character — limits on temporary fencing, motorized support for grazing operations (which require special permits), and salt and mineral placement restrictions. Motorized equipment (ATVs, motorcycles) to check on livestock in wilderness requires special authorization from the managing agency. If your allotment straddles a wilderness boundary, work with your district ranger to clarify which activities require what permits; violations of wilderness motorized-use rules can trigger permit suspension separate from range compliance issues.
If you own private land inside or adjacent to a wilderness area (an "inholding"): 16 U.S.C. § 1134 guarantees reasonable access to your private inholding — but "reasonable access" doesn't necessarily mean vehicle access. The managing agency determines access routes, and if the only reasonable access is through wilderness, the question of motorized vs. non-motorized access has been litigated extensively. Many inholding owners have negotiated access agreements or sold their parcels to the government through voluntary land exchanges. If you're considering purchasing land in or adjacent to wilderness, title review should identify inholding status before closing, as it can significantly affect use, financing, and eventual resale. The Forest Service and BLM both have land exchange programs for inholdings; contact the relevant district office or your state's wilderness coalition for guidance.
State Variations
Wilderness designation is exclusively federal, applying only to federal land:
- Alaska contains more than half of all designated wilderness (ANILCA, 1980)
- Western states have the most wilderness acreage and the most active designation debates
- Eastern states have smaller but significant wilderness areas, primarily on national forest land
- State-level wilderness or wild area designations exist in some states but do not carry federal protections
- State wilderness coalitions play a major role in advocating for new designations before Congress
Implementing Regulations
- 36 CFR Part 293 — Forest Service wilderness regulations covering prohibited uses, mining, motorized access, and commercial enterprise restrictions.
- 43 CFR Part 6300 — BLM wilderness management regulations for BLM-administered wilderness areas.
Pending Legislation
- HR 6777 — Oregon Owyhee Wilderness and Community Protection Act: designate ~924,440 acres as wilderness with grazing flexibility and local co-stewardship. Status: Introduced.
- HR 6783 — San Gabriel Mountains, Foothills, and Rivers Protection Act: designate ~28,900 acres as wilderness and add Wild and Scenic River segments. Status: Introduced.
- S 3527 / HR 6788 — Montana Sportsmen Conservation Act: remove wilderness study area designations for three Montana areas to expand access. Status: Introduced.
Recent Developments
The most significant recent wilderness legislation was the Dingell Act (2019), which designated approximately 1.3 million acres of new wilderness across multiple states. The companion Wild and Scenic Rivers system often overlaps with wilderness designations, protecting free-flowing waterways within wilderness boundaries. The debate over allowing mountain bikes in wilderness areas has intensified, with legislative proposals to amend the Wilderness Act's "mechanical transport" prohibition — none have passed. Climate change is altering ecosystems within wilderness areas, raising difficult questions about whether active management interventions (like assisted migration of species or prescribed fire) are consistent with the principle of leaving wilderness "untrammeled." The roadless rule for national forests, while not creating wilderness, provides complementary protection for approximately 58 million acres of inventoried roadless areas. Old-growth forest conservation initiatives have drawn renewed attention to wilderness and roadless area protections as tools for carbon sequestration and biodiversity preservation.
- Trump "energy dominance" and wilderness review (2025): Executive Order 14154 (Unleashing American Energy, January 2025) directed DOI and USFS to review existing federal land protections for compatibility with energy development. Because wilderness designations are statutory (enacted by Congress), the administration cannot remove them by executive order — a key legal limitation that distinguishes wilderness from monument and roadless area protections, which have executive origins. However, the order directed agencies to expedite review of mineral leasing and energy development applications on lands adjacent to wilderness areas that had previously been given administrative buffer protections.
- National Monument reductions and wilderness interaction: The Trump administration reinstated the boundaries of Bears Ears and Grand Staircase-Escalante National Monuments at their reduced 2017 Trump-era footprints (after Biden had restored original boundaries in 2021). Lands removed from monument status are now open to leasing and development, but wilderness-designated areas within the original monument footprints retain full Wilderness Act protection regardless of monument status. The monument reductions created legal complexity distinguishing wilderness-protected lands from formerly monument-protected lands now subject to leasing.
- Wildfire and prescribed fire in wilderness — management tension: Record wildfire seasons (2024: 9.4 million acres burned nationally) have intensified the debate over whether prescribed fire in wilderness areas violates the "untrammeled" prohibition. Forest Service and NPS have used the "natural fire" exception — allowing lightning-caused fires to burn under managed conditions — but authorized prescribed burns within wilderness require Wilderness Act exception analysis. The OBBBA's forestry provisions included language clarifying that mechanical fuel treatment and prescribed fire within wilderness are permissible where necessary for wildfire risk reduction, addressing a longstanding ambiguity in agency guidance.
- Mountain bike wilderness legislation — renewed push: HR 1065 (117th Congress) and successor bills propose amending the Wilderness Act to allow "non-motorized mechanized transportation" (mountain bikes) in wilderness areas — overriding the Forest Service's 1984 regulatory interpretation that prohibits bikes. The mountain biking industry (IMBA) argues modern wilderness areas were designed for foot and horse travel and should accommodate non-motorized cycling. Traditional wilderness advocates (The Wilderness Society, Sierra Club) oppose any amendment, arguing that bike infrastructure degrades ecological and solitude values. The bills have not advanced, but pressure has increased as mountain biking has grown from a niche to a $26 billion industry.