Scale 1:500,000. 1 in. = approximately 8 miles ; Lambert conformal conic projection, based on standard parallels 33° and 45° (W 91°30ʹ00ʺ--W 87°31ʹ00ʺ/N 42°30ʹ00ʺ--N 36°58ʹ00ʺ).
Note:
Also shows counties, towns, railroads, drainage, built-up areas, national forests, and national wildlife refuges. Relief shown by contours and spot heights. "Compiled in 1970." "Contour interval 200 feet." Includes "Population key."