Fine early map of the Clear Lake Area, by George H. Baker, acknowledged as one of early California's leading artists and lithographers whose pioneering work documented California's earliest history.
The map would seem to have been prepared for a pamphlet prepared in or shortly after 1875, utilizing recently prepared information from Whitney and several other maps or the region, as described below.
Our best guess is that this map may in some way relate to the series of water supply maps commissioned by the San Francisco Board of Supervisors in 1875, which were also made by Baker. These includes maps focused on the Spring Valley Reservoir, Clear Lake, Blue Lake Reservoirs, Calaveras Reservoir and a General map of the Surveys of the San Francisco Water Supply, under the direction of T.R. Allardt.