dormant:Temporarily or seemingly inactive. Dormant volcanoes erupt rarely; extinct ones don't erupt at all.
fault: A crack between two slabs of rock in the earth's crust. These cracks and fractures are weak spots where earthquakes are most likely to occur.
The northern California coast has huge redwood trees, also called sequoias. Some are 300 feet high! The Lava Beds National Monument is also in northern California, south of the town Tulelake. All the volcanoes here seem dead (or dormant), but they've left fields of dark lava, and about 200 lava caves.
North of San Francisco, the Point Reyes National Seashore is an astounding mix of cliffs, surf, and forest. In this general area, you can walk along the San Andreas Fault. The planet can split along this fault, which would probably cause a major earthquake!
California has the largest population of all fifty states, with about 33 million people. Sacramento is the capital, but Los Angeles is the state's biggest city, with about 3.8 million people within the city limits, and 9.9 million in the county!