Renowned for its brilliant sunsets and sweeping mountain vistas, the San Luis Valley in southern Colorado boasts another natural wonder: the elk traffic jam.
Colorado Parks and Wildlife this winter issued an unusual traffic advisory asking wildlife watchers to take note of their surroundings before pulling to the side of the road with cameras and cellphones brandished.
The impulse to stop is natural given the massive elk herds - some numbering in the hundreds - that tend to congregate in plain view along Colorado 159 in southeastern Costilla County, near the town of San Luis.
But those dazzled onlookers are also to blame for several "near misses" this year in which motorists nearly have caused crashes while stopping for a glimpse.
"Drivers on 159 are traveling at a high speed, and they're not expecting another car to be stopped on the roadside," Conrad Albert, a district wildlife manager in the San Luis Valley, said in a new release.
YouTube videos captured by residents and visitors show a different form of "elk traffic jam" - the kind in which traffic stops dead while elk dash across the road by the dozens.
On the Facebook page for Great Sand Dunes National Park & Preserve, for example, a surveillance video posted roughly two years ago shows more than 100 elk moving over the ridges, becoming the most-viewed item on the park's page.
Elk in the San Luis Valley most frequently are seen early in the morning or late in the afternoon, moving from the mountains to the plains.
"When I'm driving into work, I don't necessarily see the elk; I see the evidence of them crossing the road from the mountains into the grasslands," said Kathy Faz, a park spokeswoman.
The healthy elk population has much to do with the epic landscape.
Spanning some 8,000 square miles, the San Luis Valley is rife with food sources and hiding areas, including the national park, several wildlife refuges and the rugged Sangre de Cristo mountains, whose unpredictable weather, remote canyons and steep grades make hunting difficult.
"We would like for these animals to be dispersed more, but in the winter elk have a tendency to bunch up and find protected areas," said Joe Lewandowski of Colorado Parks and Wildlife, estimating the largest herds at 600 to 700 elk. "They're smart critters."
Elk aren't the only wildlife churning up traffic in the valley.
A similar viewing opportunity - and potential threat - exists with a herd of bighorn sheep that congregate along Colorado 149 south of Creede in Mineral County, near the area known as Wagon Wheel Gap.
A small herd of Rocky Mountain bighorns have moved close to the road and are easy to see, according to Parks and Wildlife, which urged admirers to be careful when stopping for a picture.
For wildlife viewing tips, go to cpw.state.co.us/.