Visitors to Hemenway Park in Boulder City get up close and personal Friday afternoon with two desert bighorn sheep. The small, quiet park overlooking Lake Mead has become a hot spot for watching the sheep. The best time to see the animals is between 10 a.m. and 4 p.m. Photos by John Gurzinski. Desert bighorn sheep graze Friday afternoon at Hemenway Park in Boulder City. Scientists are studying what effect Southern Nevada's booming population might have on the sheep. Desert bighorn sheep graze Friday in Hemenway Park in Boulder City. A desert bighorn sheep enjoys an afternoon snack of grass from Hemenway Park in Boulder City on Friday.

A loud crack rings out as two rams butt horns.

A herd of bighorn sheep scatter throughout the grassy field.

"Wooh! They're getting feisty," says June Krohn.

She and husband John were watching the action at Hemenway Park in Boulder City on Friday.

The couple brought Bill and Norma Leonard, their friends from Phoenix, to share one of their community's treasures: wild -- and easily viewed -- bighorn sheep.

The sheep mean a lot to locals. Families, couples and even tour buses routinely stop by the park, the optimal sheep viewing spot to observe Nevada's state animal. The animals also have been credited with bringing more business to the small city.

The interaction between visitors and sheep has worked out well for both parties for quite some time, but Kathy Longshore, a biologist with the U.S. Geological Survey, said Southern Nevada's booming population might cause problems for the sheep.

Longshore, who has been studying the movement of the sheep the past two years, said recent data suggest that new mountain bike paths and hillside construction might disrupt the steep environment where the animals live.

The sheep need to live in steep hills in order to evade predators and other disturbances, but the increase in cabins and homes, as well as traffic, pose threats to them, she said.

Increased traffic and additions to the Boulder City Mountain Bike Trail have also caused inconveniences for the sheep. Pat Cummings, a scientist with the Nevada Division of Wildlife, said the sheep don't know what to do about the motorcycles and mountain bikes zooming through their habitat, so they've avoided the area.

Cummings said the sheep are good at adapting, but since they are fully surrounded by towns, there's not really anywhere for them to go.

Longshore said it's far too soon to worry about the sheep abandoning Boulder City, but it's an issue that local biologists are concerned about. That's why her group has put GPS-tracking collars on sheep in about six herds to find out if their movement has been affected.

So far, Longshore said the study hasn't produced any concrete results, but a report is expected by December.

Because the sheep aren't going anywhere anytime soon, the biggest concern is how to interact with them, Cummings said. Judging from the growing popularity of the park, that interaction is expected to continue.

Joani MacLain, a tour guide with Comedy on Deck tour groups, said tourists enjoy seeing the sheep because it's something that isn't available in many parts of the country.

"People love to see him," she said. "It's sometimes hard to drag them away."

Sue Vargochik, who works in Boulder City, said she comes to the park overlooking Lake Mead almost every day on her lunch break as a way to relax and a take a break from work.

Others, like Boulder City resident John Krohn, like to see how close they can get to the animals.

"I saw one come as close as 10 feet away from me," he bragged.

"But he's not that bright," joked Norma Leonard, a friend of Krohn's.

"Yeah, he doesn't care if he gets butted," June Krohn said about her husband.

Longshore warns about getting too close to the sheep. She said she doesn't recall anyone ever being injured by one of the animals; they don't let people get too close. But minor communicable diseases can easily spread to sheep, causing big problems, she added.

"People like to see the sheep, but it's not always good for the sheep," she said.

Still, it doesn't seem to stop people. Some residents even leave out buckets of water for the sheep.

Roger Hall, director of Boulder City Parks and Recreation, said Hemenway Park is also a popular spot for weddings, with pictures of big horn sheep romping in the background.

Even local business operators like the wild animals.

Jill Lagan, chief executive officer of the Boulder City Chamber of Commerce, said visiting sheep watchers have meant increased business in town. Many of the visitors shop, and stop for dinner afterward.