The pictures are crude. Some are painted, others chipped in rock panels. The two slightly curved lines on top of the head of a four-legged animal most certainly identify bighorn sheep.

Bighorn sheep were, in fact, a vital resource for early Utahns. And, judging from the number of sheep on a single panel, they were numerous.

They provided food, clothing and tools and were more plentiful than either elk or deer.

There was a time, however, in the early 1960s, when it was believed Utah had no more bighorn sheep. There were no reported sheep sightings.

Biologists believe diseases, carried by the bighorn's cousins, domestic sheep, were the main cause of their demise.

What they eventually found was that surviving sheep escaped the threat by moving to some of the most inaccessible, most hostile country in Utah — the Colorado River corridor.

It was, remembered Jim Karpowitz, then a new biologist assigned to the Southeastern Region of Utah, who is now director of the Utah Division of Wildlife Resources, "somewhat of a surprise."

"When I first started the job, there were very few sheep in Utah," he remembered. "What they did was moved into areas where they could survive. There were few sightings."

From that small group of sheep, Utah started a recovery program that is, today, one of the state's true wildlife success stories.

The current population in Utah is estimated at more than 5,000 sheep, representing three genetic species — desert bighorn, Rocky Mountain bighorn and California bighorn, which is often included in the family of Rocky Mountain sheep. The Rocky Mountain and California sheep are so close genetically that are often listed as a single species.

Rocky Mountain sheep are nearly twice the size of desert bighorn. A Rocky Mountain ram can weigh up to 300 pounds. Ewes of both species are about 40 percent smaller.

Early rock art, going as far back as the 1300s, depicts four-legged animals with curled horns and human figures nearby with bow and arrow. History tells us Father Escalante wrote about bighorn sheep in his journals as he passed through southern Utah, as did John Wesley Powell on his exploration of the Colorado River.

Domestic sheep came into Utah with the Spanish explorers and stayed.

The problem, said Karpowitz, "is centered on the meeting of two worlds. Domestic sheep are old world and bighorn sheep are new world and simply have no resistance to the diseases domestic sheep have become immune to over time.

"Domestic sheep and wild sheep simply can't co-exist, even today."