Zion National Park • Blame humans for the first time desert bighorn sheep disappeared from Zion National Park. The second time, the animals wandered off on their own.
And now, they're back.
Bighorn sheep, native to Utah's rugged canyon country, were spotted in Zion until the 1950s, when a combination of human factors likely led to their demise. For years, the only sightings in the park were the many petroglyphs portraying the animals.
In 1973, a dozen desert bighorn sheep were reintroduced to Zion from Lake Mead. They initially were kept in pens so they could acclimate to their new surroundings.
Their numbers grew to about 20 and they were released only to vanish.
"The transplant was basically deemed a failure," said Jason Nicholes, a biologist with the Utah Division of Wildlife Resources.
Then, in the mid-1990s, Zion visitors started spotting the sheep again. Counts pegged their numbers at about 50. More than a decade later, reports of wild sheep came from south and east of Zion at Mount Carmel Junction, Hildale and Kanab.
"Maybe there were more sheep than we thought," Nicholes said.
An aerial count in fall 2008 confirmed that the transplanted bighorn, ghosts for decades, had been thriving in and around the park. In two hours, biologists counted 75 sheep.
The next year, DWR biologists conducted a full survey in Zion and lands to the south. Their findings: 114 bighorn outside the park and 115 inside.
Today, Zion visitors regularly spy wild sheep in and near the Checkerboard Mesa area on the park's southeast portion.
"Seeing a bighorn is one of the climax experiences for people visiting Zion," said Claire Crow, the park's wildlife program manager. "They are a relatively large and kind of foreign animal for most people. They are also special because so much of the wildlife at Zion is not easily seen because they are active at night or dawn and dusk, but the bighorn are accessible during the day and from the road."
Besides being a treat for visitors, the sheep play a role in the park's ecosystem.
"They may not be a keystone species, but if you take them away everything is completely different," Crow said. "It is important for natural places to provide the whole natural ecosystem rather than just a part of it."
Other groups also have taken notice of the booming bighorn population.
The Utah Wildlife Board launched a desert bighorn hunt for fall 2010. The first was limited to five permits with holders allowed to hunt south of the park between Interstate 15 and Highway 89 and south to the Arizona border.
Four of the five hunters took bighorn rams and another two animals were killed by hunters packing the high-auction conservation permit and the sportsman's tag. All six of the bighorn sheep were considered trophies with horns large enough to make the Boone and Crockett record book.
The wildlife board recently approved nine permits for fall 2012.
"Hunting is designed as a management tool, and it works as a management tool when it is handled properly and they know the appropriate limits of harvest," Crow said. "Hunting, however, is not part of the management within the park."