So I got down today and measured up the Garos general store.
The building is currently covered with composition shingles and narrow (1-1/2") window and door trim. Under the shingles (at least on the two side walls) are wood shakes with wider 4" trim, and under those are 5" clapboard. Truly a most interesting building.
Here's a picture showing the Strohmeyers installing the shakes over the clapboard in the 30's (note the bundle of shakes leaning against the fence, and the tar-paper between the clapboard and shakes):
and a couple of pictures (also from the 30's) showing the finished shake walls:
(All pictures Park County Archives.)