Jared Ogden, Professional Climber

The Karakoram mountains of Pakistan are home to K2, the world's second highest peak at 28,251 feet. For Ogden, a world-traveling expedition climber, the range's skyscraping granite spires, including the Great Trango Tower and Shipton Spire, make the Karakoram an archetypal and incomparable place. "I've never seen such beautiful mountain architecture as in this range," he said. The Karakoram is one of the highest mountain ranges in the world, too, with dozens of peaks stretching above 20,000 feet in elevation.

Vince Anderson, Professional Climbing Guide

Straddling the Alaska/Yukon border, the St. Elias Range features snowy and socked-in mountains stretching nearly 20,000 feet into the sky. For Anderson, the range exemplifies all things wild, rugged, remote and vast. "It is a true mountain wilderness with huge glaciers, high peaks, big relief and much wildlife," he said. Being close to the ocean, the range offers some of the biggest vertical relief on the planet. For example: Mount Saint Elias, at 18,008 feet, is just ten miles from the icy waters of a sea-level fjord.

Abby Watkins, Professional Climbing Guide

Older and more remote than the Rockies, though much less known, the Selkirk Mountains of British Colombia extend north from Idaho far into the wilds of Canada. Deep forests, abrupt mountain faces and glaciers are part of the allure. Watkins loves the range's alpine climbing and backcountry powder skiing. "The glaciers are big, the rock is good quality and the skiing in winter is unbeatable," she said.

Will Gadd, Professional Climber/Paraglider/Writer/Producer

Gadd has traveled to most of the major mountain ranges in the world. But the Canadian Rockies, especially the Canmore-Mt. Robson corridor, is his favorite alpine destination. Rock and ice climbing, as well as high alpine mountaineering, are part of the appeal. "These mountains are truly wild," he said. Gadd noted that it's possible to hike hundreds of miles in this range without ever crossing a road. He said picking a top route in the Canadian Rockies would be like "choosing a favorite dish from an unimaginably large buffet."

Vera Schulte-Pelkum, Climber/Geophysicist

As a working geophysicist and a climber, Schulte-Pelkum said she has developed a personal relationship with the Colorado Front Range of the Rocky Mountains. This line of mountains, extending south from the Wyoming border into Colorado, features several summits above 14,000 feet. The steep terrain provides alpine, rock and ice climbing--as well as skiing--nearly year-round, according to Schulte-Pelkum. She also has a soft spot in her heart for the range's geologic past: "The high peaks are flanked by the remnants of an older mountain range that was lifted up in a collision with the supercontinent Gondwana and then completely eroded away before the dinosaurs showed up on the scene."

Ed Viesturs, Professional Climber

Seattle-area resident and renowned professional climber Ed Viesturs has summitted the 14,410-foot Mount Rainier 198 times. "It offers so much variety and gives you a taste of the Himalayas, especially in winter," he said. Viesturs trained for years on the mountain's flanks, guiding groups on moderate routes and pushing limits on extreme and exposed ridgelines. Though Rainier often steals attention, Viesturs said the Cascades are full of hidden gems, including Mount Adams, Mount St. Helens and the sharp granite spike of Mt. Stuart. "No other range in the lower 48 has this variety."

Alaska Range

Jack Tackle, Professional Climbing Guide

This 400-mile-long mountain range in south-central Alaska is a mountaineering paradise, with extraordinarily remote routes that are as technical and challenging as anything on the planet. The range's most well-known peak is the 20,320-foot Mount McKinley. Tackle first visited the Alaska Range in 1979; he's since returned dozens of times for 11 significant first ascents. "The Alaskan Range can be Himalayan in scale," he said. "Plus, there is the benefit of having almost 24 hours of daylight in the summer months for continuous push ascents."

Kevin Thaw, Professional Climber/Writer/Speaker

The mountains of Argentine Patagonia--specifically the spires of the Fitzroy/Cerro Torre massif--are archetypal granite peaks that cut a sharp silhouette on the South American sky. Jaw-dropping heights, including vertical faces that fall away for almost a mile straight down, make this area a climbing mecca. For Thaw, who has climbed in Patagonia almost every year since 1998, the 10,280-foot Cerro Torre exemplifies the region's absurd alpine allure. "Dr Seuss might conjure a caricature that looked all too similar to this peak," he said.