Guy Wagner knows the value of a good fence. In the gated communities of Rancho Mirage—where palm trees sway against the blue sky and lawns surround the white-stuccoed houses like emerald-colored pools—he is pleased with what he doesn't see these days. A few years back he routinely found bighorn ewes and lambs munching and frolicking on the manicured parkways. "Sheep have lived here for at least the last 10,000 years," says Wagner, a biologist with the U.S. fish and Wildlife Service. "So they think they belong here—they do belong here. But people live here now too, and they don't want the sheep on their lawns, eating their roses, falling into their swimming pools and dying."
To keep man and beast apart, the fish and Wildlife Service helped Rancho Mirage build a high fence on the hillsides to block the animals. The sheep, endangered peninsular bighorns, had been coming down from the desert canyons to feed in the valley. Fewer than 700 remain in California.