Water Quality Criteria for the Madison River near West Yellowstone, Montana

Under the Clean Water Act, the surface waters in Yellowstone National Park are classified as Outstanding National Resource Waters. Under the Montana Water Classification System, these waters, located wholly within national park boundaries, are designated as A-1, or Outstanding Resource Waters in Montana (Administrative Rules of Montana 17.30.617). Exiting the park near West Yellowstone, MT, the Madison River has been classified as B-1. Water bodies classified as B-1 are suitable for drinking (after conventional treatment); full contact recreation; growth and propagation of salmonid fishes and associated aquatic life, waterfowl, and furbearers; and agricultural and industrial water supply.

Madison River water quality monitoring results are compared to the following federal and state water quality standards as well as the watershed specific total maximum daily load (TMDL) and water quality improvement plan:

EPA National Recommended Water Quality Criteria

Environmental Protection Agency (EPA). 1987. Quality criteria for water 1986 [The Gold Book]. EPA440/5-86-001. U.S. EPA, Office of Water Regulations and Standards, Washington D.C.

Montana Numeric Water Quality Standards – MT DEQ Circular DEQ-7

Montana Department of Environmental Quality. Final 2020 Water Quality Integrated Report

Administrative Rules of the State of Montana 17.30.617

Madison Nutrient, E. coli, and Metal TMDLs and Water Quality Improvement Plan

Montana Rule 12.5.507 Angling Restriction and Fishing Closure Criteria