or Mount Lassen
Volcano, southern end of the Cascade Range , northeastern California, U.S. It erupted on May 30, 1914, and intermittently thereafter until 1921.
The peak is 10,457 ft (3,187 m) high and is the principal attraction of Lassen Volcanic National Park, which occupies an area of 106,372 acres (43,047 hectares). In 1821 Luis Argüello, a Spanish officer, became the first European to discover the peak. It is named for Peter Lassen, an explorer who guided settlers through the area.