Basically, there are many herds of bighorn sheep in California mountains and deserts. The Desert Bighorn lives mostly south of the Sierra Nevada Range, and it has a thinner wool coat and is a smaller animal. The Sierra Nevada Bighorn tends to be found higher up in the mountains, so it has a thicker wool coat. Some of the big rams can weigh 200 pounds, but an adult female is more like 110-120 pounds. The Sierra Nevada Bighorn has been an endangered species (Ovis canadensis) for a while, but careful protection and management has brought them back from the brink of near-extinction.
The San Gabriel Mountains is one range just north of the Los Angeles Basin, and about 400 sheep live there. Since so many tax dollars have gone into protecting and managing sheep in the mountains, there are several agencies that manage the bighorn sheep survey each year. California Fish and Wildlife takes an interest in this, because if too many sheep are present, it will have to issue more hunting permits. The various National Forest people take interest, because sheep live in the national forests. The Bureau of Land Management gets involved a little out in the desert, because it sets up some water sources for the animals.
Each year around March, they have a bighorn sheep survey in the San Gabriels. This is since April is the right season for baby lambs to be born, so they want to survey adults in March. When the lambs are tiny, the ewes tend to keep them up very high and out of sight of predators and away from domestic sheep disease. Not too much different from humans, I suppose. Volunteers make up the survey teams, and the teams are led by representatives of the various agencies plus various bighorn sheep foundations and clubs. So, that’s why I was in the San Gabriel Mountains running around in bad weather and over slippery terrain, carrying heavy telescopes and lenses. Our team counted and identified about 13 animals, and the statistics were turned in. One ram was identified by our team, but I think the ram was surveying the humans. Photo in the online photo gallery, shot with a 150-600mm lens on a Canon 7D body.