Location Chesaw, WA
Client Garco Construction
Project Value $18 million
The Buckhorn Gold Mine was estimated to contain 100 million ounces of deposits and had a mine life of between 7 and 8 years. The facility is located in Okanogan and Ferry counties and is comprised of a combination of private property, lands belonging to the State of Washington, and partial lands in the Okanogan National Forest. During its operational life cycle, Buckhorn Mine produced nearly 500 tons of ore and 1,500 tons of development rock per day.
The surface facilities project at Buckhorn Mine accommodated underground mining and transport of ore to temporary stockpiles at the surface. The mine included 42.6 acres of new surface disturbance within a fenced area of 294 acres. The mine site layout included 3 portals including a lower (main) portal at an elevation of 5,050 feet above mean sea level (amsl), an upper portal located at an elevation of 5,450 feet amsl, and a final portal (Gold Bowl) located near the main portal. Key components of the mine site included mine portals; ventilation raises; underground workings; mine ventilation equipment; office, shop, and change-room facilities; substation; fuel storage and tank; explosives storage; development rock and temporary ore storage; backfill stockpile and batch plant; topsoil stockpiles; water tank/well; water treatment plant; storm water diversion, capture, and infiltration structures; security fencing; and parking.
Hill provided CPM scheduling for the multi-building, multi-portal project. The project was carried out on a fast-track basis and faced several challenges due to the site’s remote location and the sudden acceleration of the project to capitalize on rapidly rising ore prices. The project scope included a 600,000 CY excavation, a 38,000 LF high-density polyethylene pipe, multiple portal entrances, 3 structural steel buildings, 4 pre-engineered structures, mine water collection and treatment facilities, a 225,000 gallon domestic water tank, a process water system, concrete batch plant, and civil infrastructure.