On July 23, Mark Smiley posted this pulse-pounding video to Vimeo, depicting a portion of the ascent of the Devils Thumb, a more than 9,000-foot peak near the Alaska-British Columbia border.

The Devils Thumb is a notorious mountain, famed for its northwest ridge, which has never been successfully climbed. Jon Krakauer devoted two chapters of his well-known book "Into the Wild" to his own solo ascent of the east ridge of the Devils Thumb in 1977. His descriptions of the Thumb are foreboding:

I owned a book in which there was a photograph of the Devils Thumb, a black-and-white image taken by an eminent glaciologist named Maynard Miller. In Miller's aerial photo the mountain looked particularly sinister: a huge fin of exfoliated stone, dark and smeared with ice. The picture held an almost pornographic fascination for me.

The Devils Thumb is also featured in another book that is famous in its own right, even if it's never been made into a Hollywood movie. "50 Classic Climbs of North America" is just what it describes -- 50 climbs recommended for any mountain climber, some short and relatively easy, others challenging for even the most experienced climbers. The Devils Thumb falls into that latter category.

But the Devils Thumb was not the first ascent that Mark Smiley and his wife Janelle have completed from "50 Classic Climbs." It wasn't the second or the third, either. The Devils Thumb was the thirtieth climb that they'd attempted, in their quest to be the first people to ever finish all 50 of the climbs, a quest that will take them from the Yukon to California and back.

According to Mark Smiley, the mission to climb all 50 was something that he and his wife just kind of fell into. 

"The first time I ever heard of a classic climb was during a rock and mountain guide course," 30-year-old Mark said by phone from Wyoming Thursday. Another climber told Mark that he'd completed "20 classics in 20 days" before.

"I was like, 'what's a classic?'" Mark said. "Then I looked at the list online, and I thought, I climbed three or four of those. That’s cool. Then I started doing some research and realized that nobody had ever done all 50."

Luckily, Mark's wife Janelle is a ready climbing partner. He proposed to her atop the South Early Winters Spire in Washington six years ago, what he described as her first serious climb. Now, they offer guide services from their home base in Crested Butte, Colo. They chronicle their quest to climb all 50 on their blog, "Committed: Climbing North America's 50 Classics." In Wyoming, they'd just completed the North Ridge of the Grand Teton, their 33rd climb.

There are two things that any description of "50 Classic Climbs" points out: one is that the guide has become known simply as "the book" in climbing circles, and the other is that due to the book's popularity, the ascents included in it have become known as the "50 crowded climbs."

Mark Smiley said that they've run into some of that overcrowding. Some of the climbs are crowded, he said, because of very narrow weather windows favorable to climbing in the region, like the 10,512-foot Bugaboo Spire in British Columbia, which he and Janelle tackled in August.

"They're hit or miss on whether they're busy or not," Mark said, adding that some of them only get climbed because of their inclusion in the book. 

"For example," he said, "the Lotus Flower Tower in (Canada's) Northwest Territories, nobody would go up there if it weren’t in this book." The Smileys also climbed that peak in August. Mark downplayed some of the book's role in popularizing specific climbs, noting that "climbing in general is just gaining in popularity."

While the pace of their mission has been pretty breakneck -- they climbed or attempted to climb 27 peaks in 2010 -- "These expeditions are expensive," Mark said, and they'll need some form of sponsorship in order to keep it up. And they have big plans for the coming years, even as the ideal climbing season for 2011 comes to an end and winter begins setting in.