Quaternary Geology of Ohio, Map SG-1, by R. R. Pavey, R. P. Goldthwait, C. S. Brockman, D. N. Hull, E. M. Swinford, and R. G. Van Horn, 1999. 41- x 40-inch format, scale 1:500,000 (1 inch equals about 8 miles), full color. This large-scale map replaces and updates the Glacial Map of Ohio, first published by the U.S. Geological Survey in 1961, and consolidates the improved understanding of the state's glacial legacy.