The 1,400-acre Summitville Mine site is a former gold mine in Rio Grande County, Colorado. Gold mining started in the late 1800s. By 1984, the Summitville Consolidated Mining Corporation Inc. began open pit mining for gold, copper and silver. Mining processes, waste disposal practices, and the discharge of large amounts of copper and other metals to Wightman Fork and the Alamosa River contaminated soil, surface water and groundwater with heavy metals. Following cleanup, operation and maintenance activities are ongoing.