1/29/2026: The FEIS and appendices will publish in the Federal Register on Friday, February 6, 2026.
8/28/2025: The video from the 8/19/2025 Grassy Mountain Mine Public Meeting can be found on the Documents page under heading DEIS Public Meeting and Comment Period.
Frequently Asked Questions:
1. Will the project deplete local groundwater?
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
2. Is there a risk of arsenic contaminating drinking water?
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
3. Will contaminated materials be left behind?
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
4. Are there permanent liquid waste ponds that could leak?
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
5. How does the project protect wildlife and sage grouse?
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
6. Will the site be safe after mining ends?
Yes. The tailings impoundment will be permanently closed using engineered methods, covered, and vegetated; to protect 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.
7. How will the chemicals be transported to the mining site?
Transporters of certain quantities of hazardous or toxic materials must register as licensed transporters per US DOT and Oregon DOT (ODOT) regulations and renew registrations and fees annually. Calico will confirm vendors are licensed to haul hazardous materials as part of the initial contracting process. Requirements for contracting will include bills of lading, placarding, and established procedures and training of employees, and other applicable DOT requirements for shipments of hazardous or toxic materials to the Project. The GRASSY MOUNTAIN MINE PROJECT Toxic and Hazardous Substances Transportation and Storage Plan can be found on the Documents page for further information. Many of the hazardous materials will be coming from Winnemucca with the travel route along Hwy 95 and/or Hwy 78 to Hwy 20 through Malheur and/or Harney Counties to Vale and then down the access route to the mine site.
August 8, 2025
BLM seeks input on proposed Grassy Mountain Gold Mine
VALE, Ore. — The Bureau of Land Management is seeking public comment on a proposed gold mine and processing facility in Malheur County.
The Grassy Mountain Gold Mine Project would be sited on public and private lands approximately 22 miles south of Vale. Construction and processing would take place over a 10-year period followed by four years of reclamation and 20 years of monitoring.
If approved, Paramount Gold Nevada could develop an underground mine, dedicated mill, and associated storage on approximately 469 acres of BLM-administered land. Additionally, some existing BLM roads would be upgraded to access the operation.
The BLM is holding a public meeting on Aug. 19, in Vale at the Vale BLM District Office, and it includes a virtual attendance option. Please contact Larisa Bogardus at 541-219-6863 for details.
Additional information, including the draft environmental impact statement, is available at the BLM National NEPA Register, where comments may be submitted through the ‘Participate Now’ option (preferred). Comments may also be delivered to Attn: Grassy Mountain Gold Mine Project c/o Malheur Field Office, 100 Oregon St., Vale, OR 97918, or submitted to [email protected]. The 30-day comment period will close Sept. 8, 2025.
For more information, please call the Vale District Office at 541-473-3144 or email [email protected]
Grassy Mountain Mine Public Meeting
Tuesday, August 19, 2025
Vale District Office
100 Oregon Street
Vale, OR 97918
5:00PM to 7:00PM MT
Online Meeting Link:
Link: https://zoom.us/j/97814001896?pwd=aLqaWsXBT134SSxsqQDeOnFk4FROCL.1
ID: 978 1400 1896
Passcode: 340497
March 18, 2024
The BLM hosted two public meetings as scoping for Grassy Mountain.....
The Bureau of Land Management announces a 30-day scoping period for the project.
The BLM is requesting scoping comments on the overall project itself, and not necessarily on the Notice of Intent. Please use the "Participate Now" button to the left of this window to leave a comment.
This 30-day scoping period ends on April 17, 2024.
There will be two public scoping meetings for the project.
The first public scoping meeting will be on Wednesday, April 3, 2024 from 5p to 7p, MT at the Vale Senior Center, 100 Longfellow St. South, Vale, OR, and virtually via Zoom through this link: https://blm.zoomgov.com/j/1614889482?pwd=RXVPZXliSEZFcGp2NTZnVEpxMnFEUT09
The second public scoping meeting will be on Thursday, April 4, 2024 from 11a to 1p, MT at the Jordan Valley Lions Hall, 902 Bassett St., Jordan Valley, OR. There will not be a virtual option as there is no cell service for a hotspot.
