Jirsa, M.A.Runkel, A.C.Chandler, V.W.2010-04-012010-04-011994https://hdl.handle.net/11299/60049Scale 1:250,000. See also Miscellaneous Map M-92, 1999, which is a limited revision of this map, in that it is available in digital formats, has a different scale (1:200,000), the eastern boundary is extended several miles to long. 95o30'W., and teh geology of the region has been slightly revised. Map M-80, 1994, has a more detailed description of map units, as well as a discussion of the regional geology.en-USMap