Hi, Hilma Koski sounds familiar. There is an Otto Koski that lived near Rocky Mountain House, Alberta, Canada. He was my grandfather's, Gust Kojola's, friend. Note: My grandfather and a lot of other Finns 1st worked in the mines in Butte, Montana then went to the mines in Cumberland, Wyoming. Finally homesteading in the Red Deer / Rocky Mountain House / Eckville / Sylvan Lake areas of Alberta. There is a Finnish cemetery, Kuusamo Cemetery, in the Sylvan Lake / Eckville area. You may find Hilma Koski and others buried there. See website: albertacanadianheadstones.com for pictures of the graves. Also check out the 1911, 1916 and 1921 Canadian Census records.
When the Finns came to Alberta, they also worked in the coal mine in Nordegg, Alberta.
Hope this info. helps.