Long-distance hiker Trevor Thomas is blind, yet he's recently completed the nearly 500-mile Colorado Trail, which winds from Denver to Durango. Thomas, who lost his sight a decade ago, braved storms and long days with his guide dog, Tennile. They even found time to go off the trail and ascend Mount Elbert, the tallest peak in Colorado.

Thomas, a North Carolina native who studied at the University of Colorado, said he relies on the help of strangers as much as his determination to succeed. He's known as "Zero-Zero," which comes from hiker jargon for no visibility.

Both Thomas and Tennile came to CPR studios in Centennial, Colo., for an interview with Colorado Matters' host Ryan Warner.