SWEETWATER STATION, Wyo. — The wagon wheel ruts are still visible in places. Even after 150 years, they mark the toiled struggles of thousands of pioneers who settled the West.

And while they are well off modern highways, these parallel grooves in the sand and clay are again attracting tens of thousands of pioneers from around the world who seek to relive the experiences of their ancestors.

But in a twist of history, the new trekkers — mostly members of The Church of Jesus Christ of Latter-day Saints — are making their own tracks and endangering parts of the original trail.

Some areas of the trail started "looking more like a road than a historic trail," said Jack Kelly, manager of the Bureau of Land Management office in Lander.

In a mutual desire to protect the trail, the BLM and the LDS Church agreed to curtail the church-sponsored journeys — but not do away with them altogether.

This summer's first wave of church trekkers started out Wednesday. Over a 28-mile stretch of the Mormon and Oregon pioneer trails, they walk or pull handcarts modeled after ones Mormon pioneers hauled over the trail from 1846 to 1869.

"We're lucky in Wyoming because so much of the trail is intact," said Lloyd Larsen, stake president for the LDS church in Riverton. "We've seen just a huge increase in interest over the last 10 years. I think people are intrigued by the past. If you understand the past, it gives you some direction for the future."

The original Mormon trail extended 1,300 miles over five states, beginning in Nauvoo, Ill., and traversing Iowa, Nebraska, Wyoming and into Utah. Faced with religious and political violence in Illinois, including the shooting death of church founder Joseph Smith, some 70,000 Mormons led by Brigham Young migrated west over the trail to settle in the Salt Lake Valley.

The exodus occurred before the Transcontinental Railroad was built. Some traveled by wagon train. Those who couldn't afford the wagon train built wooden, two-wheeled handcarts that held food, cooking utensils, extra clothing, a tent and bedding.

In Wyoming, the Mormon trail enters in the southeast part of the state, heads northwest to Casper and then southwest to Utah. Along the way are such landmarks as the Mormon Ferry, built by the first group of emigrants led by Brigham Young; Independence Rock, on which the names of pioneers are still clearly engraved; Devil's Gate, a unique narrow passage; and Martin's Cove, where Mormon pioneers took refuge after being caught in a fierce snowstorm that killed more than 100 of them in October 1856.

"It's just an intriguing saga this country has been blessed with," Larsen said.