The Siakumne and the Seguamne are subject to some confusion. This difficulty arises partially from the similarity in name. The Siakumne are called Si-a-kum-ne by Merriam and Sakayakumne by Kroeber. In Gatten's census of 1846 they appear as Sagayakumne. In the San Jose baptism book we find Ssicomne, Zicomne, Siusumne, and Sigisumne. The Seguamne, on the other hand are designated Seguamnes and Saywamines by Merriam and Sywameney or Seywameney by Sutter in his New Helvetia Diary (1939). Gatten calls them Sywamney. They appear in the San Jose record as Secuamne, Seguamne, Seyuame, and other variants.
The Siakumne lived somewhere between the Calaveras and Stanislaus rivers according to Merriam, who places one of their villages at Knights Ferry on the Stanislaus. Schenck doubts Merriam's location and Kroeber puts the rancheria Sakayakumne as far north as the Mokelumne. Sutter (1939, p. 88) says that some of these people came to work for him, an unlikely event if they had been living as far away as the Stanislaus. It is probable that the lower Calaveras River is as close as we can place them. The Seguamne are not mentioned at all by Schenck. Merriam (Mewko List, MS) says they were a "tribe or subtribe on E. side lower Sacramento River" and may have been a subtribe of the Bolbones. Sutter and Gatten both refer to the tribe, and the sphere of activity of these men did not extend much below the Sacramento River itself. Hence, although there are grounds for including the Seguamne with the Bolbones or the Cosumnes, no serious error will be committed by placing them in the Mokelumne group.
The Moquelumnes were unquestionably quite numerous. In Spanish and Mexican times they were the most aggressive and belligerent of all the valley tribes and gave the coastal settlers a very rough struggle. Nevertheless, in spite of their detestation of the missionaries they furnished 143 converts between 1817 and 1835. At a ratio of 10 per cent this would mean a population, prior to the mission period, of about 1,400 souls. J. M. Amador (MS, 1877, p. 43) says that once, during the later colonial period, they furnished 200 auxiliaries, a fact which would argue fully 1,000 people at the time. Gatten in his census of 1846 gives them a total of 81 persons but G. H. Tinkham says that in 1850 or thereabouts they possessed four sizable villages with four chieftains. This may have meant between 200 and 400 persons, a really considerable number of survivors for a tribe which had suffered so extensively in the preceding three decades. These indications, and it must be admitted that they are only indications, would lead one to infer that the aboriginal population reached at least 1,500.
Precisely because the Moquelumnes were so brutally handled in the colonial era the modern ethnographic accounts of villages are very incomplete. Neither Merriam nor Schenck gives us any list. Kroeber puts three on his map (1925, opp. p. 446): Mokel (-umni), Lelamni, and Sakayak-umni. I think we are now in a position to state that these names represent former tribes and if they were applied to villages by informants, it is because the component units had shrunk to very small size.
Stream density comparisons are of value for the Mokelumne group. On the Cosumnes River, from Sloughhouse to Thornton, Merriam shows thirteen rancherias (omitting those close to the Sacramento River). As was proposed above we may ascribe from 200 to 400 inhabitants to each of these, say on the average 300. Now there is no reason to suppose that the Mokelumne River from the San Joaquin-Calaveras county line to just west of Lodi was less heavily populated than the Cosumnes. If so, the number of villages per linear river mile must have been very nearly the same. For the stretches under consideration there were 24 miles on the Cosumnes and 22 on the Mokelumne. Thus we would get 12 villages and 3,600 persons living on the Mokelumne River.
The Yatchikumne and, if we are to credit Schenck, the Passasimas occupied a position on the Calaveras River comparable to that occupied by the Moquelumnes on the Mokelumne. Schenck regards the Yatchikumne as a tribe equal in importance to the Moquelumnes, and the county historians speak of them as a large group. Their river frontage is equivalent to that of the Moquelumnes. For these reasons we would be justified in ascribing to the Yatchikumne and Passasimas the same population as the Moquelumnes, i.e., 3,600. The evaluation of the other two groups from the geographical standpoint is difficult, owing to the uncertainty of their location. The Siakumne may be regarded as living somewhere on the lower Calaveras and, if so, must be included with the Yatchikumne and Passasimas in the estimate for the Calaveras. The Seguamne may or may not have inhabited the banks of the Mokelumne and Calaveras rivers. In view of our ignorance on this point it may be well to omit them from consideration in this connection and leave the estimate with the existing total of 7,200.
We may attempt some direct tribal comparisons. In considering the northern San Joaquin Valley and delta 21 tribes and tribelets have been examined, namely: Aguastos, Bolbones (4 tribes), Leuchas, Ochejamnes, Guaypen, Quenemsias, Chuppumne, Chupunes, Tarquines, Julpunes, Ompines, and the Cosumnes group (7 tribes). For all these the average population calculated has been very close to 700. If this figure is applied directly to the Moquelumne group, its population becomes 3,500. However, some adjustment is necessary. The Moquelumnes by all accounts, Spanish and American, were an unusually large tribe, probably reaching at least 1,500. The Yatchikumne may not have been as numerous but were apparently above the average size, let us say 1,200. The Passasimas, despite the fact that Schenck thinks they were a "group plus" may be regarded as smaller, perhaps no more than average. For the Siakumne and Seguamne we must also assume the average figure, 700. With these adjustments the total reaches 4,800.
The baptism books give us a record of the following conversions.
| Tribe | San Jose | Santa Clara |
|---|---|---|
| Moquelumnes | 143 | ... |
| Yatchikumnes | 118 | ... |
| Passasimas | 145 | ... |
| Siakumne | 22 | ... |
| Seguamne | 47 | 116 |
The Passasimas, Siakumne, and Seguamne were situated in the vicinity of the San Joaquin River and hence were more exposed to the Spanish expeditions than the tribes along the lateral streams. Hence the proportion of those taken for conversion may have been higher than the 10 per cent of the aboriginal population found for the Cosumnes, although it would not have attained the value of 50 per cent characteristic of the more westerly delta tribes. We may take an intermediate figure, 20 per cent. This would give the Passasimas a population of 725, the Siakumne 110, and the Seguamne 815. The great disparity between the figures for the last two tribes may well be due to confusion of names in the mission records. The total for the three is 1,650. For the Yatchikumne on the Calaveras River no more than 10 per cent baptisms can be assumed, yielding a population figure of 1,180. If only geographical location were considered, the same factor could be used for the Moquelumnes but this tribe resisted missionization with extraordinary tenacity. Hence we are not justified in using a factor of more than 7 per cent, from which we may infer that the population was 2,040. The baptism data would then give us a total for the group of 4,870.