Which preposition to use with siwashes

from Occurrences 1%

Then there were Siwashes from Vancouver, Cassiars from the Gold Mountains, Teslin men, and even Sticks from the Yukon Country.

in Occurrences 1%

From the broad east windows of their house she saw all the traffic that came and went on the upper reaches of Roaring Lake, Siwashes in dugouts and fishing boats, hunters, prospectors.

Which preposition to use with  siwashes