Lassen Volcanic National Park 106,372 acres (43,081 hectares), N Calif., at the southern end of the Cascade Range. Proclaimed as Lassen Peak and Cinder Cone national monuments in 1907, the two were incorporated into a new national park in 1916. The park contains volcanic peaks, lava flows, vents, and hot springs. Lassen Peak, 10,457 ft (3,187 m) high, is officially an active volcano even though the last major eruption occurred in 1914; it was intermittently active until 1921. The peak was a prominent landmark in the mid-1800s for westward travelers to California. See National Parks and Monuments (table).