All the Pomoan languages were originally spoken in northern California, primarily in Sonoma and Mendocino counties. This map shows the original tribal boundaries overlaid on a modern Google map (click map for larger version).
The next map shows the Kashaya tribal territory based on the same map. This is roughly as described by Oswalt (1961), based especially on the linguistic origins of local placenames. Some sources place the upper boundary further north at Gualala (rather than Black Point, as on this map), and the lower boundary also further north at the Russian River (rather than Salmon Creek).