Scale 1:500,000. 1 in. equals approximately 8 miles ; Lambert conformal conic projection based on standard parallels 33° and 45° (W 89°34ʹ17ʺ--W 81°57ʹ53ʺ/N 39°08ʹ50ʺ--N 36°29ʹ49ʺ).
Note
Shows county seats, county boundaries, and drainage; does not show roads. Relief shown by shading and spot heights. "Compiled in 1956." "M R-1451."