Colorado and mining have a long history together. The gold rush in the late 1850s brought an unprecedented number of people and mining operations into the region. Most of Colorado’s mineral mining activity predates the passing of current environmental regulations in the 1970s and 1980s.
Before this time, many mining companies did not sufficiently restore mined areas, leaving physical hazards and environmental impacts. High levels of metals released to streams from acid mine drainage can harm fish and aquatic ecosystems. These contaminants may also impact drinking water and agricultural water sources. These problems are ongoing in Colorado.
By most accounts, there are over 23,000 abandoned mines across the state and 1,800 miles of streams impaired due to mine related pollution.