The Upper Animas Watershed is formed by Mineral Creek, Cement Creek and the Upper Animas River. The three tributaries join to form the Animas at the town of Silverton. Historic mining practices have led to high heavy-metal loads in the Animas, and these tributaries have carried metals like iron, aluminum, zinc, cadmium, copper and lead into the river, threatening human and aquatic life. The Animas River Stakeholders Group has evaluated sites throughout the watershed and monitored streams for metal loads. The following are some of the issues with the upper watershed.

• On Mineral Creek, low-flow analysis determined that more than 70 percent of the zinc loading in the creek originates from the area around Red Mountain Pass, which includes the Kohler Mine site.

• Five sites in Mineral Creek also have been identified by the group as priority sites for drainage- and hydrologic-control projects. This involves channeling water away from waste piles and possibly removing certain piles.

• In the Cement Creek drainage, the Sunnyside Gold Corp. has plugged the Sunnyside Mine portal and is treating the upstream waters of Cement Creek. The company also has removed tailings in the Gladstone area in accordance with its Mined Land Reclamation Permit.

• An agreement between Sunnyside Gold and the Environmental Protection Agency provided for the historic preservation of the Mayflower Mill. Thousands of tons of mine tailings have been removed from the floodplain and placed in a permanent repository in the area.