The Elevation 12473 is shown on the Mt. Pinchot USGS 15 minute quadrangle. The SPS peaks list and many other references show the elevation as 12,451 ft., or 3795 meters - obviously derived from the eastern summit elevation. The western summit is clearly higher when viewed from the eastern summit.
From Sawmill or Armstrong, go to "Colosseum Col" west of the summit for a class 1 ascent up Colosseum's west ridge. There are several class 2-3 shortcuts up from the valleys north and south of Colosseum Col.
The north ridge (from Armstrong Col) is variously described as class 3 by Secor, class 4 "generally chosen in error" by Voge-Smatko, class 4 by Roper, class 3-4 by Matthew, and "nasty" or "really nasty" by Nile. See Nile's detailed report at climber.org
Sawmill Pass is one of the best kept secrets of the Eastern Sierra. We met a guy named Don camped at the beautiful Sawmill Meadow who said it was his 45th year in a row coming there(!!!) and he almost never saw anybody there in May. Sawmill Lake is a magnificent place to camp and fish. Then, just over the pass you can see the lovely Woods Lake. What keeps the secret so well is the first 4 miles of trail. It starts out going through dry brush and cactus at about 4500 ft. elevation. We had no trouble starting out at 1030 am on an unusually cold Memorial Day weekend, but Kathy says starting at 5 am in June was too late to avoid the heat and misery of going uphill on a sandy trail with no water for so long. After that, it's glorious ( at least it is in a wet spring season). Some places, grass is growing in the middle of the trail, which to me, is a rare and treasured sign of the peace and solitude to be found there. I hope it stays that way.
Armstrong Canyon has no quota (and no trail), but you still need a permit for overnight trips starting there. If you take a large group, they might suddenly tell you there's a quota.
Approved bear-resistant containers are required for camping in Kings Canyon National Park, but not in the National Forest in Sawmill Canyon or Armstrong Canyon, but you are still required to protect bears from access to your food, by counterbalancing it or using a bear-resistant container, etc. Check with the rangers in advance to get the current requirements.
See http://www.fs.fed.us/r5/inyo/recreation/campgrounds.shtml for car camping.
There's a "Sawmill Creek Campground" shown on the USGS Topo where Tinemaha Road (old 395) crosses Sawmill Creek, but I don't recall seeing it as I drove by - I believe it's defunct. The Goodale Creek Campground is listed as the nearest campground by http://sierranevadawild.gov/modules/html/trailheads/sawmill_pass.htm
See an artificial aerial view of Sawmill Pass and Colosseum Mtn., etc., at http://geogdata.csun.edu/sierraweb/sierra_nevada-Pages/Image84.html
A little kit of information for my trip to Colosseum is at http://www.langenbacher.org/Sawmill
See also http://www.langenbacher.org/Armstrong for stuff about the approach through Armstrong Canyon.
John Muir "The Wild Sheep" 1881
Colosseum Mountain is in a "California Bighorn Sheep Zoological Area", as shown here, but it is not in an area that is closed to hiking at any time.
I have read that "Sierra Nevada Bighorn are rarer than the Florida Panther or the California Condor. They are clearly one of the most endangered mammals of North America."
You can read something about them at http://www.dfg.ca.gov/ocal/archives/bighorn_sheep_jf04.pdf, or at http://www.sierrabighorn.org/ .
The US Fish and Wildlife Service "Final Recovery Plan for the Sierra Nevada Bighorn Sheep" of Feb. 13, 2008, is here. They do consider the Bighorns to be seriously endangered, but they make these statements which would be of interest to mountain climbers:
Actions to ameliorate the effects of human/recreational use were not given high priority in this plan because we do not currently consider recreational use, including the activities of dogs, a significant threat to Sierra Nevada bighorn. If information indicating recreational use is having an effect on recovery becomes available, appropriate actions will be recommended.
Although we recognize the potential of recreation to impact bighorn sheep, these impacts seem to be minor. However, the recovery plan calls for continued monitoring of the compatibility between recreational use of bighorn sheep habitat and bighorn sheep recovery