Liberty Ridge slopes from the Carbon Glacier toward the summit at a 45-degree angle. It's so steep, Whitaker said, that some rescue parties prefer to lift stranded climbers to the summit, then descend via an easier route.
The plan to rescue Cooley called for lowering him down the ridge had they not been able to reach him by helicopter.
"It's as high-risk as any other rescue on the mountain," said Mike Gauthier, commander of the rescue.
Whitaker and Gauthier describe the area as a steep ridge surrounded by ice cliffs and a feature known as Willis Wall. It's a favorite climb of both men.
The climb became more popular in 1979 when it was listed in the book "Fifty Classic Climbs in North America" by Steve Roper and Allen Steff.
"Climbers come from around the world to tick that one off," Gauthier said.
Liberty Ridge is one of the toughest routes to the summit, though it is not as difficult as its neighbor, Willis Wall.
Whitaker, the son of climbing legend Lou Whitaker, says it is so challenging because it so steep for such a long stretch.
Cooley and his partner, Scott Richards, left Thursday afternoon from Ipsut Creek in the northwest corner of the park, and Cooley fell Saturday morning. The first rescue unit left Ipsut Creek on Saturday night and reached Cooley and Richards on Monday afternoon.
Gauthier says it typically takes three to four days to reach the summit via Liberty Ridge. Easier routes typically take two days.
Gauthier says the rescue was "incredibly stressful" because of the difficulty of the terrain.
"It's not an easy rescue," Gauthier said. "I have to say the rescuers are heroes."