Throughout much of the summer and early fall, the only human visitors to explore the upper reaches of Imogene Pass are those seated in a 4x4 vehicle or atop an OHV. On Saturday, however, the high altitude stretch of rocky dirt road connecting the towns of Ouray and Telluride will see a flood of human travelers of a different sort.

Wearing colorful hues of polypropylene and powered by only their blistered feet, more than 1,500 runners are expected to tackle the lofty task of competing in the Imogene Pass Run, which begins Saturday at 7:30 a.m. in Ouray.

Touted as the benchmark among high altitude trail runs, the IPR is a grueling, 17.1-mile race that, despite its difficulty, draws a sell-out crowd every year.

Race Director John Jett reported Wednesday that registration stood at 1,533 runners, a number consistent with registration numbers from the last few years. More than 65 runners are from the Telluride region; large contingents of runners are also making the trip for the race from Durango (108 runners), Boulder (115), Denver (190), and Flagstaff, Ariz. (220). Runners from 35 different states will race the pass, as well as a few from other countries.

"We have better than a 50 percent return rate for this race," Jett said. "The Imogene is what a lot of local racing clubs base their entire training schedule around."

The winner of the 2003 and 2004 Imogene Run, Bernie Boettcher from Silt, Colo., will be making a go at winning the Imogene's "triple crown" this year. Last year's female winner, Najeeby Quinn, will also take a stab at a three-peat Imogene win.

Many of the Telluride Imogene Pass Run faithful will be making their umpteenth appearances at the popular race, including longtime local Jerry Greene, who will continue his reign as the runner with the most consecutive Imogene Run starts in the race's history (aside from race founder Rick Trujillo of Ouray) as he steps up to the starting line for the 27th time tomorrow.

Other IPR faithful, like Kari Distefano and IPR board members Dave "Sam" Samuelson and Tom Kenning, will be joining the large field of runners. This will be Samuelson's eighth time running the IPR. Coming to Telluride from California with a strong marathon background, he said the IPR first struck him as a remarkable race due to its longstanding popularity.

"What's amazing to me about this race is that it really is not an easy run," he said, "but it sells out in one week! People are just clamoring to do it."

Since the race's humble beginnings in 1974, when Camp Bird Mine worker Trujillo and friends raced from Ouray to Telluride over the Imogene Pass jeep road, little about the course has changed as it climbs to a height of 13,114 feet and crests the summit of Imogene Pass. The sale of the Camp Bird Mine property, currently underway, could possibly change the course in the future, however.

"The sale of the Camp Bird Mine could potentially impact the race significantly," said Jett, "if the new owners decide not to continue to offer the property for runners in the Imogene." Today's course follows the drainage up through the Camp Bird Mine property, cutting off more than a mile from the normal jeep route, which traverses further into Yankee Boy Basin.

Jett said that although the IPR board has not yet heard whether the new ownership of the property will change the IPR course in the future, they are hopeful that the new owners will continue to offer the property for use during the annual event. "This is such a longstanding tradition," he said, "we're hoping the new owners will invite us to pass through there in the future."

Proceeds from race registration fees are fed directly back into the Ouray and Telluride communities. Funds raised at the IPR are used to support community organizations such as Search and Rescue of San Miguel and Ouray counties, Montrose Amateur Radio Club, Telluride Ski and Snowboard Club, and Ouray and Telluride track teams, gifted in the form of scholarships or direct monetary donations.

"It really does feel good to distribute the money right back into the community," Samuelson said.

Race registration is closed, but Jett said that a great way to experience the race is as a volunteer. A crew of nearly 200 volunteers is needed to put on an event the size and caliber of the IPR. Volunteers are still needed to man the six aide stations scattered along the race route. For more information or to sign up as a volunteer, call Jett at 728-0251 or visit www.imogenerun.com.

Racers can be expected to cross the finish line at Oak St. and West Columbia Ave. in Telluride from late morning through early afternoon.