Grassy Mountain Mine permitting

Client Name
Calico Resources USA Corp
Vale, Oregon, USA
  • Mine environmental & social
  • Mine technical services
  • Environmental management, permitting & compliance


The Grassy Mountain Mine project is in Malheur County about 20 miles south-southeast of Vale, Oregon. The project proposed will be an underground gold mine and an indoor processing facility.

The initial notice of intent was filed in June 2012, followed by baseline study collection plans, and filing of a consolidated permit application in November 2019. In February 2020, the company received the completeness review noting it as incomplete and requiring additional information.

SLR was hired by Calico in October 2020 to respond to the comments and submit a new application. SLR joined the project to assist with the Oregon regulatory experience complemented with the mining strength.


  • Streamline the approval process with Department of Geology and Minerals Industry (DOGAMI)
  • Prepare the Plan of Operations (PoO) and modified Consolidated Permit Application (CPA)
  • Resolve insufficiency findings from the agencies and coordinate with consultants utilized by Calico with the prior submittal
  • Author or prepare regulatory plans associated with the permit


SLR coordinated and led virtual meetings with the individual agencies and client to engage in discussion regarding clarity of the CPA and PoO comments and needed information.

SLR coordinated an onsite field visit at the proposed mine site with the state agencies, BLM, Calico, and key consultants. The field visit was beneficial for understanding and visualizing the project and building the bonding of the large team.

SLR authored or provided technical review of over 50 supporting plans and documents. Subject areas covered stormwater, groundwater, wastewater, waste management, hazardous materials, personnel safety, transportation, emergency preparedness, design plans, closure and reclamation and wildlife mitigation strategic to the project.

SLR’s expertise in the Oregon regulatory environment and the vast experience in mining has been key to working collaboratively with the regulatory stakeholders.


The CPA and PoO are currently under review by DOGAMI and BLM respectively. Acceptance of both the PoO and CPA is anticipated in fourth quarter 2022. SLR has and continues to support Calico with environmental permitting and compliance with this project.