The Grassy Mountain Gold Project is a proposed underground gold mine located in Malheur County, Oregon, developed by Paramount Gold Nevada Corp. The project includes mining operations, a processing facility, water and power infrastructure, and site reclamation.

It is located approximately 22 miles south of Vale, Oregon, within the Bureau of Land Management (BLM) Vale District.

Paramount Gold Nevada Corp. is the project proponent. The permitting process is led by the U.S. Bureau of Land Management (BLM), in collaboration with state and federal agencies and Tribal governments.

The project is designed to produce approximately 41,000 ounces of gold and 52,000 ounces of silver annually over an estimated 9.3 year mine life. Ore will be extracted from underground workings and processed through a 750 tonne-per-day (tpd) milling operation that utilizes carbon-in-leach (CIL) recovery technology. The process is expected to achieve gold recovery rates of approximately 93% and silver recovery of around 78%.
In addition to metal production, the project incorporates robust environmental protection measures and a comprehensive reclamation plan to ensure responsible resource development and long-term site restoration.

The Final Environmental Impact Statement (FEIS) is the completed federal analysis of the Grassy Mountain Gold Project's potential environmental effects. The Bureau of Land Management (BLM) issued the FEIS on January 29, 2026, alongside the Record of Decision approving the project.

The FEIS builds on the Draft Environmental Impact Statement (DEIS), which was released in August 2025 for public review. During the comment period, federal, state, and local agencies, Tribal governments, and community members provided input on the proposed project and alternatives. The BLM reviewed all comments and incorporated responses into the final document.

The FEIS reflects nearly a decade of scientific studies covering water, wildlife, air quality, cultural resources, and socioeconomic factors. It represents the culmination of the federal environmental review process under the National Environmental Policy Act (NEPA) and supports the BLM'''s decision to approve responsible development of the project.

The full FEIS is available on the eplanning.blm.gov.

The project is designed to minimize impacts to local ranching and agriculture. The DEIS confirms that groundwater use will not significantly affect nearby wells, and robust containment systems will protect against water contamination.

To safeguard grazing lands, the project will include secure fencing around the disturbance area to prevent livestock access and ensure ranching operations can continue safely nearby. A full reclamation plan will restore land post-mining. The Company is committed to responsible development that coexists with local agricultural use.

Yes. The project is expected to generate local jobs, support small businesses, and contribute to the regional tax base. Local hiring and procurement are part of Paramount Gold’s commitments.

If the Grassy Mountain Project is approved, we would work closely with local fire, ambulance, and emergency management agencies to develop appropriate emergency response procedures, coordinate emergency preparedness, and help ensure safe, reliable site access. Protecting the safety of our employees, contractors, and the surrounding community would remain a key priority throughout the life of the project.

Yes. Tribal governments have been formally consulted as part of the NEPA process. The DEIS includes an analysis of potential impacts to cultural and historical resources.

Paramount Gold is required to follow cultural resource protection laws. If new discoveries are made, work will pause and appropriate protocols will be followed in coordination with Tribal authorities.

No. The project’s water use (72 gallons per minute annual average over the life of the operating mine) is well below the 900 gpm water rights approved by the Oregon Water Resources Department. These rights have been held since the 1980s and make up ~95% of the basin’s allocation. Studies show stable groundwater levels.

The project includes state-approved monitoring and mitigation plans to protect springs and other users.

Grassy Mountain Mine Project: Draft Environmental Impact Statement, Section 2.2.1 and 3.11.1.2

Elevated arsenic levels are naturally present in groundwater near the mine, with years of baseline monitoring showing concentrations consistently above federal drinking water standards. The city of Vale is more than 20 miles away and lies in a separate groundwater basin, making impacts to its water supply extremely unlikely. Any water or waste produced by mining will be stored in engineered containment systems built to meet or exceed state and federal environmental standards. These systems are monitored throughout the life of the mine and will be permanently sealed at closure to ensure long-term protection of the surrounding environment. Therefore, the risk of the mining operation causing any arsenic contamination over the already elevated baseline is extremely low.

Grassy Mountain Mine Project: Draft Environmental Impact Statement, Section 3.11.1.4

Grassy Mountain Gold Project Groundwater Reports; SPF Water Engineering, LLC, December 8, 2021

The mining wastes, such as tailings and waste rock, are natural materials and do not contain added chemicals. While they can potentially react with water and air, the tailings will be managed in engineered containment facilities designed for long-term environmental protection. Waste rock will be used to backfill the underground mine. All non-mining materials (e.g. trash, used tires, broken equipment, construction/demolition debris, residual chemical like lime, etc.) will be removed at closure. No chemicals used in the mining and gold recovery process will remain onsite after mining ends.

Grassy Mountain Mine Project: Draft Environmental Impact Statement, Section 2.2.4

Cyanide leaching will be used in a facility that is contained and isolated from the environment to meet international best practices in safety for cyanide usage.

The beneficiation process involves grinding ore into fine particles and mixing it with water to create a slurry for gold recovery. The slurry after gold recovery is called tailings. Water separates from the tailings solids in a lined facility and is continuously recycled to reduce groundwater use. All mining wastes and water are stored in engineered containment systems designed to meet or exceed regulatory standards, minimizing the risk of leakage. At closure, water is removed from these facilities before they are permanently sealed using engineered methods to ensure long-term environmental protection.

Grassy Mountain Mine Project: Draft Environmental Impact Statement, Section 2.2.4

The project is located outside core sage grouse habitat, on the edge of a low-density habitat zone. The underground design significantly minimizes surface disturbance. The project’s wildlife mitigation plan describes how the project will comply with ODFW’s GRSG habitat mitigation program which requires compensatory mitigation for impacts to this species and its habitat. Additional wildlife protection plans have been approved by ODFW and other agencies.

Wildlife Resources Baseline Report; EM Strategies, October 2020
Revised Wildlife Protection Plan; Mason, Bruce and Girard, Inc., July 20, 2022
Revised Wildlife Mitigation Plan; EM Strategies and Mason, Bruce and Girard, Inc., August 2023

Yes. The tailings impoundment will be permanently closed using engineered methods, covered, and vegetated; to protect the environment. No chemicals used in the mining and gold recovery process will remain, and all surface infrastructure will be removed. Reclamation will meet strict state and federal standards to ensure the site is safe, stable, and environmentally sound long-term.

Please see the project timeline here.

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Yes, for ease of reference, please see the list below: