English: Map of Montana in the northwestern United States — showing notable ancient glacial lakes of the last ice age period in North America.
Information based on: Alden, W.C. Physiography and Glacial Geology Of Eastern Montana and Adjacent Areas. Professional Paper 174. Washington, D.C.: U.S. Geological Survey, 1958; Lemke, R.W.; Laird, W.M.; Tipton, M.J.; and Lindvall, R.M. "Quaternary Geology Of Northern Great Plains." In The Quaternary of the United States. H.E. Wright, Jr. and D.G. Frey, eds. Princeton, N.J.: Princeton University Press, 1965; Stickney, Michael C. "Quaternary Geology and Faulting in the Helena Valley." In 1987 Guidebook for the Helena Area, West-Central Montana: Guidebook for the 12th Annual Field Conference. Richard B. Berg and Ray H. Breuninger, eds. Montana Bureau of Mines and Geology Special Publication 95. Helena, Mont.: Montana Bureau of Mines and Geology, 1987.
{{Information |Description={{en|1=Map of Montana in the United States, showing notable ancient glacial lakes of the last ice age period. Information based on: Alden, W.C. ''Physiography and Glacial Geology Of Eastern Montana and Adjacent Areas.'' Profess