The Division of Wildlife Resources released 18 of the Rocky Mountain sheep - after fitting them with radio collars and ear tags - at the mouth of Grove Creek Canyon in the shadow of Mount Timpanogos.
Onlookers formed two lines from the sides of a trailer and leading up a small hill. Sen. Margaret Dayton, R-Orem, opened the trailer doors, and the wild sheep galloped through the middle of the small crowd, then over a hill and into the mountains.
Thursday's release - expected to be the year's last - marked the continuing return of the indigenous animals and was part of a wildlife swap with Colorado in which Utah handed over moose in exchange for the 17 ewes, 15 of which are pregnant, and one ram.
DWR is expanding the bighorn sheep population in northern Utah County's mountains between Battle Creek Canyon and Alpine City. The first release occurred in 2000, and the count now is up to 80, but DWR officials hope to introduce 125 to 200 bighorns so the population can sustain itself through natural mortality.
"When the pioneers came, bighorn sheep were the most prolific big-game sheep in the area," DWR wildlife biologist Craig Clyde said. "We lost those sheep and want to get them back on the mountain. We want wildlife in wild places."
But, through the years, over-hunting and diseases from domestic sheep began wiping out the indigenous population. Many contracted a fatal Pasteurella pneumonia and were unable to survive in the mountainous region from the 1940s until recently, when officials eliminated the domestic sheep population.
Now the most serious danger to the sheep probably will come from coyotes, cougars, bears and eagles. But DWR officials say they have reduced the number of cougars to give the sheep a fighting chance.
DWR spokesman Scott Root said officials originally caught too many rams and not enough ewes, which are desired for breeding purposes.
"It's kind of like all species, the males aren't worth much," Clyde joked.
Root added that wildlife swaps between states are not uncommon. He said Utah has traded other wildlife, such as fish for turkeys.
The bighorn sheep were marked with a white tag on one ear to distinguish them as high-elevation animals from Colorado, and orange, yellow or green tags on the other to mark their age.
The plastic radio collars will allow Brigham Young University student Justin Shannon to track the sheep, which generally reside at elevations around 10,000 feet in the winter and higher in the summer. He will study their habits and habitats and whether they mix with other herds of wild sheep in the mountains.
"I'll figure out their home ranges and put it on a topographical map," Shannon said. "It's always rewarding to see sheep going up on the mountain."
Shannon said the bighorns usually won't come down to the mouth of the canyon, near 5,000 feet, where the neighborhoods are.
"But sometimes they'll come down and play king of Bunker Hill on people's Corvettes," Clyde said.
Dayton, who sits on two natural resources committees and co-chairs the wildlife-backing Sportsmen's Caucus, got the honor of opening the trailer Thursday, releasing the sheep.
"It felt good," Dayton said. "But I'm glad they didn't knock me into the mud."