Ore extraction in and near Neihart left a legacy of pollution and physical danger. Tailings, the fine-grained leftovers from crushing and chemically treating ore to extract metals such as silver, have been found in isolated places in and near the town and contain metals that can be harmful to people and wildlife if exposure levels are high. Historic mine sites also contain hazards including open shafts, unstable adits, and derelict structures. In September 2001, Neihart and the adjacent watersheds of Carpenter and Snow creeks were added to the federal Superfund priority list for cleanup funds, and Cascade County and the town of Neihart, with help from the Montana Department of Environmental Quality and the U.S. Environmental Protection Agency, have minimized pollution risks, though physical hazards remain. At the same time, mining played a major role in Montana’s development: the state seal bears the motto “oro y plata,” the arrival of railroads in the late 19th century enabled industrial mining, demand from the industrial revolution in the United States and Europe drove use of Montana’s mineral resources, Neihart became a major producer of silver and lead, and during the 1940s its mines produced large quantities of lead and zinc in support of the war effort.