5. Bo-i-os. These were located "south of Booldam River on the coast," in other words south of Big River near the boundary between the Northern and Central Pomo.
Since the region of Ukiah, Hopland, Booneville, Point Arena, and Fort Ross was well explored and even extensively settled by 1855, it is entirely probable that Heintzelman recorded all the existing natives of the area. Regardless of terminology the five names above leave no important fraction of the territory unaccounted for. Heintzelman's total for the population is 2,100, a figure which should be compared with the value of 6,220 obtained through the use of village lists, together with house and family number.
For the Athapascan and Yukian peoples, as well as for the Northern Pomo, a marked correspondence could be observed between the two sets of data, even though entire identity could not be achieved. For the Central Pomo, on the other hand, there is a striking disparity: the Heintzelman estimate reaches only one-third the value obtained from ethnographic sources. Since Heintzelman could reach his maximum accuracy among the relatively well known Central Pomo, as opposed to the remoter northern groups, we cannot ascribe his low count to ignorance or carelessness on his part. The most reasonable explanation is that the Central Pomo had already by 1855 suffered a reduction in population of from one-half to two-thirds of the aboriginal level. Such an hypothesis is entirely consistent with all we know of Mexican and American settlement in Sonoma and southern Mendocino counties and, furthermore, tends to lend support to the much higher figures reported by Heintzelman for the more northerly tribes.
Central Pomo ... 6,220
SOUTHWESTERN POMO
This group, consisting principally of the Kacia of Stewart's Point, has already been discussed under the Central Pomo.
SOUTHERN POMO
In this area lived five large groups, named variously by different students, centering around Dry Creek, Cloverdale, Healdsburg, Santa Rosa, and Sebastopol. The Pomo residue, mentioned by Barrett, and others who survived in Alexander Valley are here omitted since they may be more appropriately considered as contributing to the predominantly Wappo population. Likewise, the village of Wilok, east of Santa Rosa, is probably considered more satisfactorily in conjunction with the neighboring Wappo.