15301 -- U.S. ZIP code Municipality (1990): WASHINGTON, Pennsylvania All ZIPs for this municipality (1990): 15301 Population (2000): 49735 Housing Units (2000): 21577 Land area (2000): 120.301849 sq. miles (311.580345 sq. km) Water area (2000): 0.275824 sq. miles (0.714382 sq. km) Total area (2000): 120.577673 sq. miles (312.294727 sq. km) Located within: Pennsylvania (PA) Location: 40.170663 N, 80.251858 W