Alaska has just 0.01 percent of the world's 6.7 billion humans. But according to National Geographic Adventure magazine, it has 13 percent of people who did the most extraordinary work this year in exploration, conservation, action sports and humanitarian efforts.

Two of the 16 people selected as the magazine's prestigious Adventurers of the Year are Alaskans. Through Jan. 15, the public can vote online for a favorite. The Alaskans are:

• Lt. Col. Marc Hoffmeister of Fort Richardson who, despite serious injuries sustained in Iraq from a roadside bomb, organized a team to climb Mount McKinley that included three other injured vets.

• Katey Walter Anthony of Fairbanks, an aquatic ecologist and assistant professor at the University of Alaska Fairbanks who mounted an expedition to Siberia to seek out and measure beds of thawing permafrost -- a major source of methane gas, a greenhouse gas that is 25 times more potent than carbon dioxide but is not yet factored into most climate change models.

In June, Hoffmeister and his wife, Gayle, were part of a team of five men and one woman that flew to the Kahiltna Glacier at the base of North America's tallest peak as part of what they called Operation Denali.

It had been just a little more than two years since Marc Hoffmeister, on patrol in Iraq with the 4th Brigade Combat Team (Airborne), saw a roadside bomb rip through his vehicle in Al Hillah, Iraq.

While fortunate to survive, Hoffmeister sustained severe damage to his left arm and suffered daily head pain. Feeling vanished from his fingers, and he lost half of the muscle mass from his arm and five inches of the ulnar nerve. From wrist to elbow, that arm is now titanium.

Besides the Hoffmeisters and a longtime able-bodied friend of Marc's, Bob Haines, the party included three other injured Iraq veterans:

• Jon Kuniholm, a former Marine who'd lost an arm to an improvised explosive device and carried two prosthetic arms with him on the mountain in case one broke;

• Matt Nyman, an Army Ranger whose leg had to be amputated after his chopper crashed; and

• David Shebib, an Army combat medic who sustained severe head and chest injuries after stepping on an IED.

To bolster their attempt, the climbers hired guides from the Alaska Mountaineering School, led by Kirby Senden of Eagle River. During their first days on the mountain, the team ironed out a few kinks: Kuniholm had to figure out how to handle the rope with his prosthetic hand; he and Nyman didn't want to share a tent because two amputees were too slow in the mornings; Hoffmeister had to remember to self-arrest with his good arm, not his bad one.

"This crew was a total inspiration, and Marc certainly was the mastermind while being a modest, team-oriented guy," said Julia March Crocetto of Alaska Mountaineering School.

Senden agreed.

"It was by far the most rewarding Denali trip I've done," said Senden, who's guided more than a dozen. "Just walking into camp with these guys was something. People would come over from all the place -- out of the blue, really -- asking for autographs and pictures in places like base camp. There were some other military groups on the mountain, and they all knew these guys."

The team took the West Buttress route, the most popular route up Denali but still a difficult climb. Only about half of the mountaineers who start on any given season reach the summit.

On the 15th day of the climb, the group was struggling but ready for an attempt on the summit. Kuniholm and Nyman had been felled by altitude sickness, leaving just the Hoffmeisters, Haines and Shebib. As they crested Denali Pass at 18,200 feet, Marc noticed that Gayle was acting hypothermic, sluggish and off balance. He noticed a spot of frostbite on her face. The climbers huddled with their guides. The decision was to retreat.

"That was the toughest part of the climb for all of us," Hoffmeister told David Roberts of National Geographic Adventure magazine. "Gayle was determined to go on. I said, 'Look, I spent a year getting my hand back, I'm not going to spend a year helping you get your toes back.'"

Hoffmeister, Shebib and Haines set out again the next day. After reaching Denali Pass and crossing the vast Football Field, they reached the summit ridge and clipped into fixed lines. But as the summit came into sight, bad weather closed in.

Before long, it was a whiteout. Locating the ridge line became difficult.

But their persistence was rewarded with summit embraces.

Then came a ceremony that may be a first for Denali. As his teammates hoisted an American flag flapping in the stout wind, David Shebib raised his hand while Hoffmeister re-enlisted him in the Army. Shebib is now on active duty in Germany, where he continues to receive medical attention.

Hoffmeister is getting set for his next climb, up Africa's tallest peak, Mount Kilimanjaro, in February. After that, he may head to Afghanistan or return to Iraq. The sweet feeling of success will accompany him.

"It's just an awesome goal for most people," Senden said. "For these guys to stick their necks out and go for it when the chips are stacked against them, I hope it motivates other military members who are injured. Everybody is going to have their own Operation Denali."

Reach reporter Mike Campbell at mcampbell@adn.com or 257-4329.

A group of 30 explorers, scientists, journalists and luminaries in the world of adventure served on an advisory board for the nomination of this year's top adventurers. The class of 2009 includes a BASE jumper, military veterans, an explorer, road trippers, a surfer, an astronaut, an ultra runner, an educator, a filmmaker and a scientist. Apart from Hoffmeister, they are:

• Khadija Bahram: Supported by the aid organization International Rescue Committee, Bahram guided an educational program that stretched across five provinces in war-torn Afghanistan and reached more than 10,000 pupils -- mostly girls, as well as disabled children.

• Stephen Bouey and Steven Shoppman: The pair crossed 69 countries and racked up more than 77,000 miles during a 2 1/2-year road trip that circumnavigated the globe by road.

• Maya Gabeira: The only sponsored female big-wave surfer in the world, Gabeira surfed the largest wave by a woman ever, landing a 45-footer at South Africa's Dungeons.

• John Grunsfeld: Known as NASA's Hubble repairman, Grunsfeld braved hurtling space debris to pull off the repair to end all repairs: Working at zero gravity some 350 miles above the surface of the Earth, the astronaut restored sight to a half-blind Hubble.

• Albert Yu-Min Lin: Seeking the lost tomb of Genghis Khan, he organized a high-risk, high-stakes project into Mongolia's so-called "forbidden zone" using state-of-the art, cutting-edge mapping technology.

• Dean Potter: He recorded the longest BASE jump ever -- 2 minutes, 50 seconds -- while wearing a wing suit that allowed him to cover some 9,000 vertical feet and nearly 4 horizontal miles.

• Louie Psihoyos: He assembled a crew to expose and end the annual slaughter of hundreds of dolphins for meat in Taiji, Japan, a story told in the award-winning film "The Cove."

• Diane Van Deren: Survivor of a successful lobectomy, Van Deren became the first and only woman to complete the Yukon Arctic Ultra, a 430-mile run that follows the route of the Yukon Quest, finishing in Dawson City.

• Katey Walter Anthony: The aquatic ecologist and assistant professor at UAF mounted an expedition to Siberia to seek out and measure beds of thawing permafrost -- a major source of methane gas, a greenhouse gas that is 25 times more potent than CO2, yet is not factored into most climate change models.