Pinyon Plain Uranium Mine (Baaj Nwaavjo I'tah Kukveni National Monument, Grand Canyon region)
Kaibab National Forest, ~6-10 miles from Grand Canyon National Park's South Rim, Coconino County, AZ · Active uranium mine grandfathered inside a National Monument (Baaj Nwaavjo I'tah Kukveni, designated 2023) · managed by U.S. Forest Service (Kaibab National Forest); Arizona Department of Environmental Quality; EPA Region 9
01 — Historical & Cultural Record
The mine (originally Canyon Mine, renamed Pinyon Plain Mine) was first approved in the 1980s under a Plan of Operations from 1986 and closed in 1992 when uranium prices fell to $6.40/lb. In 2012, Interior Secretary Ken Salazar established a temporary 20-year administrative mining ban across roughly 1 million acres of public land near the Grand Canyon. The Forest Service determined Canyon Mine held "valid existing rights" under the 1872 Mining Law, exempting it from that ban. In August 2023, President Biden designated the Baaj Nwaavjo I'tah Kukveni — Ancestral Footprints of the Grand Canyon National Monument at the request of tribes, withdrawing the area from future mineral entry; Pinyon Plain was again grandfathered in as a pre-existing right and is the only active mine operating inside the monument's boundary. Red Butte, a Havasupai sacred site near the mine, was separately designated a traditional cultural property under the National Historic Preservation Act.
02 — Current Threat
Operator Energy Fuels Resources (USA) Inc. began active ore extraction in December 2023 (first ore removed to the surface January 8, 2024) after decades of litigation, citing rising uranium prices (roughly $57/lb as of recent reporting, up from the 1992 shutdown price of $6.40/lb). Miners pierced an aquifer during shaft construction in 2016, and the mine has pumped groundwater out of the shaft continuously since. Ore is trucked roughly 300 miles across Navajo Nation land to the White Mesa Mill near Bears Ears National Monument for processing (see /sites/bears-ears/). In July 2026, the Havasupai Tribe formally objected to a proposed amendment to the mine's aquifer protection permit that would raise the allowable arsenic limit at a monitoring well, arguing Arizona regulators are attempting to weaken pollution limits without proper public process.
03 — Documented Impact: Environmental
Geology & Hydrology: The mine sits above the deep Redwall-Muav Aquifer, which feeds seeps and springs throughout the Grand Canyon and is the Havasupai people's sole source of drinking water via Havasu Creek and Havasu Spring near Supai Village. A shallower C-aquifer and the deeper R-aquifer are separated by more than 2,000 feet of rock, but numerous studies — including a 2024 published groundwater study — strongly suggest likely connectivity between them via fractures and faults.
Water & Contamination: Over the past decade the mine has pumped more than 80 million gallons of groundwater out of the mine shaft (6.7 million gallons in 2025 alone, per the company's own 2025 annual report), stored in an uncovered pond inside the site's fence. A 2024 published groundwater study found potential for contamination from the mine to reach springs on the Grand Canyon's South Rim and Havasu Spring near Supai Village, though it called for further monitoring-well data to confirm exact flow paths. A 2026 EPA technical study, requested by the Havasupai Tribe, similarly found "potential" for the mine to contaminate local and regional groundwater resources vital to the Havasupai Reservation's water supply, while stating further investigation is needed to confirm the extent of aquifer connectivity.
Habitat & Cultural Site: The mine sits near Red Butte, the Havasupai Tribe's sacred mountain, a designated National Historic Preservation Act traditional cultural property.
Long-Term Effects: Groundwater contamination from mining, if it occurs, would affect a aquifer system already documented as slow to characterize (2,000+ feet of separating rock, ongoing scientific uncertainty about connectivity) — meaning any contamination could take years to be detected and would be extremely difficult to remediate once it reaches a deep aquifer supplying a community's sole water source.
03 — Documented Impact: Cultural & Archaeological
See Red Butte traditional cultural property designation above. The mine sits within a monument designated specifically at tribal request to protect this landscape, yet operates under a legal exemption tribes have unsuccessfully litigated against for years.
03 — Documented Impact: Economic & Fiscal
Energy Fuels reported producing about 1.6 million pounds of finished U3O8 (yellowcake) at the White Mesa Mill in the first half of 2026, sourced partly from Pinyon Plain ore; because mining is currently in "lower grade areas" producing less ore than the mill can process, mill operations were scheduled to pause for Q3 2026 before resuming. A dedicated cost-benefit or taxpayer-impact analysis specific to this mine (e.g., value of foregone groundwater, monitoring costs borne by EPA/state regulators) was not identified in current sourcing.
03 — Documented Impact: Legal Status
The Havasupai Tribe's lawsuit challenging the mine's exemption from the 2012 mining ban was dismissed and the dismissal affirmed on appeal. The Tribe, Grand Canyon Trust, Center for Biological Diversity, and Sierra Club have separately and repeatedly legally challenged the Forest Service's decisions allowing the mine to operate. As of July 2026, the Havasupai Tribe was formally objecting to a proposed state permit amendment loosening the arsenic limit at a mine monitoring well.
03 — Documented Impact: Human Health
The Havasupai Tribe's core stated concern is direct: contamination reaching their sole source of drinking water. No separate occupational or community air-quality health study specific to this mine was identified in current sourcing, distinct from the water-contamination risk already detailed above.
03 — Tribal / Public Consultation Status
The Forest Service was documented as "not a part of" discussions between Energy Fuels and the Navajo Nation over ore-transport routes across Navajo land in 2024 — meaning the relevant federal land-managing agency was absent from the tribal negotiation that determined how ore moves across a second tribal nation's territory. The Havasupai Tribe's July 2026 objection to the arsenic permit amendment specifically states Arizona regulators are "not required to accept formal comments" on the change, meaning no mandated public/tribal consultation applies to that particular permit action even as the Tribe formally requests one.
04 — Named Companies & Responsible Parties
- Energy Fuels Resources (USA) Inc. (subsidiary of Energy Fuels Inc., Canada) (Mine operator; also owns the destination processing mill) — Operates Pinyon Plain Mine (17-acre site) and trucks ore approximately 300 miles across Navajo Nation land to its own White Mesa Mill near Bears Ears for processing — the same company profiled in the Bears Ears case file [~1.6 million lbs U3O8 produced at White Mesa Mill in H1 2026 (partly from this mine's ore); mine has been in planning/ownership since the 1980s]
Source: https://azdailysun.com/news/local/environment/havasupai-tribe-objects-to-aquifer-protection-permit-change-at-pinyon-plain-mine/article_c996bad6-32f9-42a4-9045-c59fde6df017.amp.html - Arizona Department of Environmental Quality (ADEQ) (State permitting authority) — Issued the mine's Individual Aquifer Protection Program Permit (No. P-100333, July 31, 2024); currently considering an amendment to raise the permitted arsenic limit at a monitoring well
Source: https://azdeq.gov/WQD/PinyonPlainMine - U.S. Forest Service, Kaibab National Forest (Land-managing agency) — Approved the mine's Plan of Operations under a 2020 Environmental Impact Statement and Record of Decision; determined the mine holds valid existing mining rights exempting it from the regional mining ban
Source: https://fs.usda.gov/r03/kaibab/forest-products/nonwood-products/pinyon-plain-mine-formerly-canyon-uranium-mine
05 — Recorded Opposition & Support
- Havasupai Tribe (Opposes the mine; has litigated against it for decades and formally objects to a 2026 permit amendment, 2026-07) — source
- Grand Canyon Trust, Center for Biological Diversity, Sierra Club (Have jointly and separately legally challenged the mine's operation, ongoing) — source
- Navajo Nation (Negotiated directly with Energy Fuels over ore-transport routes across its land; voluntarily paused transport for months in 2024 pending discussions, 2024-2025) — source
- Ute Mountain Ute Tribe (Opposes operations, citing proximity of the destination mill to their community, n.d.) — source
- Energy Fuels Resources (States mining, hauling, and processing pose no threat to communities or the environment, n.d.) — source
06 — Timeline of Developments
- 1980s Canyon Mine (later Pinyon Plain) first approved under a Plan of Operations.
- 1992 Mine halts operations as uranium price falls to $6.40/lb.
- 2012 Interior Secretary Salazar establishes a 20-year administrative mining ban near the Grand Canyon; Forest Service exempts the mine as a valid existing right.
- 2016 Miners pierce an aquifer during shaft construction; groundwater pumping begins.
- 2018 Mine shaft sinking completed to ~1,470 feet.
- 2020 USFS completes Environmental Impact Statement and Record of Decision under NEPA for the mine's Plan of Operations.
- 2023-08-08 Baaj Nwaavjo I'tah Kukveni National Monument designated at tribal request; mine again grandfathered in.
- 2023-12 Energy Fuels begins active ore extraction.
- 2024-01-08 First ore removed to the surface.
- 2024-07-30 Energy Fuels voluntarily pauses ore transport after two shipments, pending Navajo Nation discussions.
- 2024-07-31 ADEQ issues the mine's Individual Aquifer Protection Program Permit.
- 2025-02-12 Ore hauling resumes following Navajo Nation discussions.
- 2026 (H1) ~1.6 million lbs U3O8 produced at White Mesa Mill; mill scheduled to pause Q3 2026.
- 2026-07 Havasupai Tribe formally objects to proposed arsenic-limit permit amendment.
07 — Sources
Primary
- PrimaryPinyon Plain Mine, Coconino County, AZ — U.S. EPA, 2026-03-03. https://www.epa.gov/uic/pinyon-plain-mine
Supports: EPA technical study findings, aquifer connectivity assessment, request origin - PrimaryWQD | Permit of Interest | Pinyon Plain Mine — Arizona Department of Environmental Quality, 2026-05-08. https://azdeq.gov/WQD/PinyonPlainMine
Supports: Permit number, issuance date, regulatory framework, EIS/ROD reference - PrimaryPinyon Plain Mine (formerly Canyon Uranium Mine) — U.S. Forest Service, Kaibab National Forest, n.d.. https://fs.usda.gov/r03/kaibab/forest-products/nonwood-products/pinyon-plain-mine-formerly-canyon-uranium-mine
Supports: Site size, shaft depth, operational timeline, monument-exemption status
Secondary
- SecondaryUranium mining operations begin at Pinyon Plain Mine — Navajo-Hopi Observer, 2024-04-17. https://www.nhonews.com/features/uranium-mining-operations-begin-at-pinyon-plain-mine/article_9c73e602-1ab3-5663-8327-870c7f793f0a.html
Supports: Monument designation context, litigation history - SecondaryPinyon Plain Uranium Mine (formerly Canyon Mine) — story map — Grand Canyon Trust (ArcGIS StoryMaps), 2026-01-12. https://storymaps.arcgis.com/stories/e5581098559f4c9884cd76185e840b22
Supports: Full historical timeline, mining claims context, litigation history - SecondaryGrand Canyon Uranium Mine Water Problem Hits 80 Million Gallons — Grand Canyon Trust, 2026-06-06. https://www.grandcanyontrust.org/blog/pinyon-plain-uranium-mine-80-million-gallons/
Supports: Groundwater pumping volumes, arsenic permit dispute, 2024 groundwater study findings - SecondaryHavasupai Tribe objects to aquifer protection permit change at Pinyon Plain Mine — Arizona Daily Sun, 2026-07-04. https://azdailysun.com/news/local/environment/havasupai-tribe-objects-to-aquifer-protection-permit-change-at-pinyon-plain-mine/article_c996bad6-32f9-42a4-9045-c59fde6df017.amp.html
Supports: 2026 permit dispute detail, ore hauling route/pause history, U3O8 production figures - SecondaryArizona approves key environmental permit for uranium mine near Grand Canyon — Associated Press (via Yahoo News), n.d.. https://news.yahoo.com/arizona-approves-key-environmental-permit-004941170.html
Supports: Uranium price history, company ownership/incorporation details
Corrections Log
None on record as of 2026-08-12 (page initial publication).
Take Action
ADEQ's arsenic-limit permit amendment does not require formal public comment; the Havasupai Tribe and allies are urging public pressure regardless.