The geologic map of the Townsend quadrangle, scale 1:100,000, was made as part of the Montana Investigations Project to provide new information on the stratigraphy, structure, and geologic history of this geologically complex area in west-central Montana. The quadrangle encompasses about 4,200 square km (1,640 square mi).

The geologic map of the Townsend quadrangle, Montana, provides a summary of new and selected existing geologic information for public use and use by Federal, State, and local governmental agencies for land-use planning, including assessment of natural resources and natural hazards and recreational potential, and for land-use management. The geologic map is an element in the cooperative program between the State of Montana and the U.S. Geological Survey to produce 1:100,000-scale geologic map coverage for the entire State.