Only the best of the best ride this 100-mile trail between Lake Tahoe and Auburn, California – and even then, only half see the finish line.

Two hundred horsemen thunder down the California trail, riding by the light of an August moon.  The site of them would invoke images of Hidalgo or The Man from Snowy River, if it weren’t for the lycra riding pants, high-tailed Arabians and endurance saddles.  But don’t be fooled, this isn’t your little sister’s dressage competition.  It’s the Tevis Cup, also known as the Western States Trail Ride, backcountry’s greatest endurance race.

“The Tevis Cup is a true test of backcountry horsemanship,” says Tom Christofk, a race veteran.  “It’s a rugged trail that weaves in and out of forests, over rock faces, through canyons, and across rivers and streams.  It’s no ride through Central Park.”

The 24-hour, 100-mile journey over the Sierras is part race, part historical reenactment.  In 1955, Tevis-founder Wendell Robie made a bet that he could ride in one day from Lake Tahoe to Auburn, California.  To pull of the feat, he departed at 5:00 a.m. under the full moon, rode through the day and late into the night.  The next year, Robie did it again, this time with a group of friends, and the Western States Trail Ride was born.  It has run every year since, with the exception of 2008, when the threat of a wildfire caused organizers to cancel, says Mike Pickett, ride director.  But fire isn’t the only trailside hazard.

“A horse fell off a cliff once,” Christofk says.  “Some riders were traveling a narrow section of trail in a steep canyon where they encountered a rattlesnake.  The lead rider spun around and bumped into the horse behind them.  That horse lost its footing and tumbled over the edge.  Its rider bailed off in time, but the horse fell down the canyon cliff and perished.”

Rattlesnake encounters aside, the Western States Trail Ride prides itself on the welfare of its animals.  Riders stop at a number of Vet Checks, including two mandatory one-hour rest stops.  At the finish line, the first 10 horses to cross are judged for best physical condition, and the winner receives the esteemed Haggin Cup.

“The Haggin Cup is a true testament to the horse,” Christofk says.  “My goal this year is to finish in the top 10 so that my horse will qualify for it.”

Christofk has finished in the top 10 three times, an impressive feat considering that 50 percent of the 200 riders don’t finish at all. Any rider that does make it is awarded the Western States Trail Ride buckle, a badge of courage in the endurance racing field.  But to compete for the Tevis or Haggin Cup, you’re in a race against the sun as much against the clock.

“My strategy is to get through Forest Hill (the densest section of trees) so that I’m not riding through it in the pitch black,” Christofk says.  “After that, moonlight is enough to get you to the finish line.”

The Western States Trail Foundation, Tevis’s parent organization, includes 800 volunteers who build trails, organize the race and raise funds for open-space projects to expand public-trails networks.  In that light, Robie’s 100 mile ride is the greatest thing that’s happened to the backcountry between Lake Tahoe and Auburn.  Not to mention it spawned one rip-roarin’ race.

To learn more about the 54th annual Tevis Cup, held August 1, visit teviscup.org