 Dibble and Los Osos soils that cover sedimentary bedrock in the eastern and northern foothills, and Hambright and Toomes soils that cover volcanic bedrock on the west side generally are more conducive to grazing cattle than growing grapes.Suisun Valley is named after the local indigenous people, a distinct tribe known as the Suisun Indians, who spoke a dialect of the Patwin Indian language.Francisco Solano, a Suisun chief and protegé of Mexican General Mariano Vallejo, applied in 1837 to the Mexican government for a land grant covering his ancestral homeland.