Scale 1:500,000. 1 in. equals approximately 8 miles ; Lambert conformal conic projection based on standard parallels 33° and 45° (W 90°30ʹ00ʺ--W 81°30ʹ00ʺ/N 36°50ʹ00ʺ--N 34°45ʹ00ʺ).
Note:
Relief shown by spot heights. "Base map drainage modified 1974." Base map "Compiled 1957, revised 1973." Includes text and table of hydrologic units.