By C. S. Brockman, G. E. Larsen, R. R. Pavey, G. A. Schumacher, D. L. Shrake, E. R. Slucher, E. M. Swinford, and K. E. Vorbau GIS and Cartography by D. M. Powers
Geologists, geotechnical consultants, land-use planners, ground water specialists, educators, and others interested in geotechnology will find many uses for Map BG-3.(scale 1:500,000)