The California Gulch Superfund Site (the “Site”) encompasses more than 15 square miles, including the town of Leadville, Colorado, and surrounding areas where historic mining activities took place. The Site contains more than 2,000 mine waste piles, as well as the Yak Tunnel which discharges drainage from numerous underground mines into California Gulch. Heavy metals and acid released at or from the Site as a result of historic mining activities are hazardous substances that have caused injuries to natural resources. Because of this extensive contamination, the Site was placed on the National Priorities List in September 1983. The Trustees, through the issuance of a preliminary estimate of damages, determined that releases of hazardous substances from the Site have resulted in injuries to surface water, terrestrial, and groundwater resources. An interactive story map of the economic contributions from this case's restoration projects can be found here https://www.fws.gov/mountain-prairie/contaminants/upperArkansasRiver.php.