Robert's Mill at Fortine, Montana

Here's the general info about the mill, excerpted from "The Story of the Tobacco Plains Country", 1950, edited by
Olga Weydemeyer Johnson, Caxton Printers, Caldwell, Idaho: 

pp. 226-227 "The second large mill in the Fortine country was the C.B. Roberts and A.E. Boorman mill on Meadow Creek four miles west of Fortine. Around 1915 the mill town here was larger than Fortine itself. The two partners handled the timber from the woods through the planing mill. The Roberts' Mill school and church co-operated with the school and church at Fortine in many programs and affairs. A.E. Boorman, of the Boorman family well known in Tobacco and Flathead valleys for their lumbering operations, later was connected with the Northwestern Forestry Association." 

From from "Montana Its Story and Biography", Volume III; Tom Stout, editor; copyright 1921; pages 691-692: 

"Since 1906 Mr. Roberts has been interested in a valuable tract of timber land at Fortine, Montana, where he built a sawmill, constructed a logging railroad between the timber and his mill, and was busily engaged in manufacturing lumber there until November 1, 1917." 

The family did not live there the entire time, but did live there at least during the period 1914-1916, and left by 1917 or 1918, and per Tobacco Plains (see ref above) pp. 199: "In the 1920's, the schoolhouse from the deserted Robert's Mill was moved in [to Fortine] to serve as the third schoolroom." so it was all over by then.