What flatlands in california lie between the sierra nevada and the coast range

San Joaquin Valley

Explanation:

San Joaquin Valley is one of the two large valleys of California. It is the southern one of the two, with the one north of it being the Sacramento Valley. This valley is located between the Siera Nevada Mountains on the east, and the Coastal Range on the west. It is a valley where the climate is predominantly semi-arid, thus it is naturally covered by grasses, which has contributed to the valley having very deep and fertile soil. Because San Joaquin Valley has fertile soil, it is heavily used for agriculture, so the majority of it is rural, with only few cities in it, none of which is actually a large city.