The geologic map of the Butte City 7.5’ quadrangle is based on mapping summarized in the 1:100,000 scale map of the Idaho National Laboratory, U.S. Geological Survey Miscellaneous Investigations Map I-2330, by Kuntz and others, 1994. New surficial geologic mapping was completed by National Association of Geoscience Teachers (NAGT) interns, Evan Martin (2015) and Samuel Helmuth (2017). Previously published maps and associated data, by various authors, including Kuntz, M.A., Betty Skipp, M.A. Lanphere, W.E. Scott, K.L. Pierce, G.B. Dalrymple, L.A. Morgan, D.E. Champion, G.F. Embree, W.R. Page, R.P. Smith, W.R. Hackett, and D.W. Rodgers from 1994 to 2017, were incorporated into this project. The U. S. Geological Survey (USGS) Idaho National Laboratory Project Office, a field office of the Idaho Water Science Center, conducts subsurface investigations to study the Snake River aquifer at the Idaho National Laboratory. Many subsurface basalts erupted from vents exposed at the surface. Tracing the flows from the surface to the subsurface provides data for numerical models of groundwater flow and contaminant transport.