I remember when my Gramps was a carpenter for the US Forest Service. In fact, he built the (now museum) original log ranger station at Priest Lake, ID. He worked there long enough he built some lookouts TWICE. I can still remember when we went up to Gisborne Mountain in about '58 when he was finishing up the "new" lookout, with the old one he had built still there not far away
The point is, there were no portable generators, pneumatic tools, air compressors, or battery powered drills and other accessories, except in the rare circumstance that a generator could be trailered in. So these were built by HAND, except maybe for a chain saw. HAND hammers, saws, brace and bit, etc. In some cases, before helicopters became popular, some of the early projects used on site trees for the legs. ALL provisions, sand, cement, water, had to be hauled in AND OUT and on some projects was hauled by mule train.
Gisborne peak lookout
Original Priest Lake Ranger Station, now the museum
http://plmuseum.org/