Well, thanks for this post, I think. I just spent the last 4 hours on it and searching for the locations of some of the pics, the ones about the "Bucklar" ranch headquarters of the CO Bar-Babbit Ranches-in particular. Earl Forrest (author of Arizona's Dark and Bloody Ground) took some photos there in the 1920's. This location is on the west flank of Humphreys, at "the head of Hart Prairie." Having spent some time there at the TNC preserve, I have never heard of the Bucklar Ranch, and neither the current nor the archived (back to 1939) USGS topos show anything. Best I can guess, it's in the vicinity of Lew Tank or Bismark Lake, but that's just a SWAG. A couple hours on Google, and paging thru Marshall Trimble's book "CO Bar" which mentions it but doesn't give enough detail to pinpoint the location, and I'm not much closer.
Mack Hughes' memoirs, "A Hashkife Cowboy" by Stella Hughes, contains passing mention of spending a summer at Hart Prairie, and he worked for the CO Bar, so there is high possibility that he was at the Bucklar Ranch. He mentions a flowing stream, of which there are now none in this area but there are some interesting possibilities where there might have been flowing water.
What a goose chase!