The Northeastern Oklahoma Mining Natural Resource Damage Assessment and Restoration Site (NOMNRDAR Site) is a result of mining in the Tri-State Mining Region, located in southeast Kansas, southwest Missouri, and northeast Oklahoma. The U.S. Environmental Protection Agency (EPA), in accordance with the CERCLA, included the Tar Creek Superfund site in Oklahoma on its National Priorities List in 1981. Three other associated Superfund sites, located in Kansas and Missouri, are also listed on the National Priorities List. The NOMNRDAR Site was mined for lead and zinc from the early 1900s to the mid 1970s. The metallic sulfide minerals in the mines lowered the pH of the ground water that filled the abandoned mine excavations, and in 1979 the ground water surfaced through old air shafts and other openings. The acidic effluent then entered the Tar Creek drainage and spread downstream along the creek and into its associated wetlands and bottomland hardwoods and eventually into Grand Lake O’ the Cherokees. This water generally contains elevated concentrations of dissolved metals, including lead, zinc, and cadmium. Tailings piles known as “chat piles” are laced with heavy metals and are a source of contamination to surrounding soils, surface water, sediments, and ground water. Water-filled depressions caused by mine collapses, are also scattered around the NOMNRDAR Site and contain contaminated water. Trust natural resources potentially affected by contaminants at the NOMNRDAR Site include federally-listed threatened and endangered species, migratory birds and their habitat, and State and Tribal resources, including, but not limited to, soils, sediment, surface water, ground water, drinking water, plants, animals, and cultural resources.