Boulder Glacier is located on the southeast slope of Mount Baker, a stratovolcano near the Pacific coast of North America in the Cascade Range of Washington. Boulder Glacier is the sixth largest on Mount Baker with an area of 1.3 square miles (3.4 km²). It flows from the summit crater between Grant Peak (10,781 ft (3,286 m)) and Sherman Peak (10,141 ft (3,091 m)) to about 5,000 ft (1,500 m).