The last time I saw Phil Hofstetter he was standing outside a tent near the confluence of the Tatina and South Fork Kuskokwim Rivers in the heart of the Alaska Range looking a little like the Pillsbury Doughboy. This is not Hofstetter's normal appearance. A dedicated long-distance cyclist, he isn't quite as hollow-cheeked lean as some top Tour de France riders, but by the big fat standards of our time, he is definitely what most would call skinny.

He looked like the Pillsbury Doughboy there outside an Iditarod Trail checkpoint called Rohn because of something called exercise-induced edema. Many athletes will be familiar with the less drastic form of this; your feet swell a shoe size or two, or your hands balloon after prolonged exercise. In Hofstetter's case, his whole body had expanded.

When he crawled out of the tent there at Rohn, a flat spot in a steep-walled valley about as far from anywhere as you can get in North America, he was so swollen he was barely recognizable. It seemed near impossible he would get back on his fat-tired bike and pedal another 800 miles or so to Nome.

And yet that is exactly what he did. An audiologist at the Nome hospital, Hofstetter claimed to lack the money to fly home, but the truth is that if he'd paid for a flight it would have cut into the funds he was trying to raise for the Leukemia and Lymphoma Society in the name of Nome friend Nora (Ivanoff) Nagaruk. (To read more about his fundraising efforts or contribute, click here).

Hofstetter made Nome a couple weeks after I last saw him and days before the finish of the Iditarod Trail Sled Dog Race, which overshadows any and all other activity on the Iditarod trail in March. Officially, it had taken Hofstetter 17 days, 9 hours and 30 minutes to pedal from the Knik Bar, where the Iditarod Invitational human-powered ultramarathon begins each March, to Nome. Most Invitational racers, of course, only pedal or run to McGrath, the intermediary "finish line" for a 350-mile race from the shores of Cook Inlet over the Alaska Range and into the vast Interior. But Hofstetter wasn't the only one who kept going.

The 1,000-mile Iditarod Trail, arguably the most famous trail in the North, doesn't see a lot of end-to-end traffic in any year, but it always sees some. There are invariably a handful of fat-tire bikers and hikers who go all the way to the end in the Invitational, and some odd characters who head up the trail on snowmachines just to be on the trail.

About a day after Hofstetter reached Nome, Idaho's Tracey Petervary and husband Jay pedaled into the city of the golden sands. Tracey got there fast enough to set a new women's record for the Invitational race to Nome -- 18 days, 6 hours. Behind the Petervarys on the trail were hikers Tom Jarding, a 54-year-old mailman, and Tim Hewitt, a 55-year-old attorney. Both live in southwest Pennsylvania, and both have done this 1,000-mile walk multiple times. They say the simply love the wildness of the Iditarod Trail.

I passed Hewitt on the frozen Unalakleet River on the way to the Bering Sea coast. He confessed his feet were in bad shape, but he was happy and pressing on. Hewitt is a short, lean man who looks the part of an ultramarathon runner. Jarding is taller and bigger boned and less obviously an endurance athlete. But he is every bit as fit. He walks a 12-mile mail route five days per week and usually runs around 10 miles per day after work.