OK - follow-up. He was using a panoramic camera, and made a whole series of photos, most of them stitched in pairs for an especially wide view. The 1911 mule train went in from the east side over Kearsarge Pass, to several well-known viewpoint locations including Bullfrog Lake along the way, and down Bubbs Creek to the East Fork branch. There are other panoramic pictures of the Kings- Kern Divide from a greater distance.
What makes all this interesting is that it was well before Ansel Adams did any of his own work in the area, which was highly instrumental in the formation of Kings Canyon National Park later, and certainly long before the Muir Trail or other convenient approaches. Kearsarge Pass like many others was used by native Americans for thousands of years before, then by early sheepherders; but would have been more difficult to cross than now, though hardly one of the more difficult passes of the area. I was last in that area last summer, but couldn't do much due to all the unhealthy smoke. I also grew up in that area, but on the western slope. I knew quite a few old timers and very old Indians who roamed and explored parts of that range long before that became a recreational thing, or anything resembling the Sierra Club existed. Knew one old Indian who had crossed an even higher more difficult pass barefoot as a teenager.
There are specialty dealers in this kind of early California photography. The one here is seldom open due to poor owner health. The Oakland Museum is a major holder of such collections.
Check out owensvalleyhistory.com : Vintage High Sierra Panoramas page. I have my own early photos collection.