From the frozen tip of Alaska through the lush jungles of Central America and down the steep peaks of the Andes Mountains, daredevil cyclists brave the Pan-American Highway each year. The paths are all different; some travelers chose to take the scenic Pacific Coast, others rode the rugged Rocky Mountains. While each rider goes for a different reason, few who complete the trip regret leaving.

Biking from the northern coast of Alaska to Ushuaia, Argentina, the southernmost city in the world, native Chicagoan Matt Kelly trekked the 17,500-mile Pan-American Highway in 21 months. He left Chicago in June 2009 and flew to Alaska, where he set out for his voyage in the beginning of July. He didn’t return home until April 14, 2011. While it’s not a formal event, Kelly said dozens of people make the journey each year, some alone, others in groups.

After taking numerous bike trips around the Midwest, Kelly wanted to take cycling to the next level. Although biking closer to home was enjoyable, he said it always meant being back in Chicago and at work on Monday morning. Reading other cyclists’ stories and blogs inspired him to take on the Pan-American Highway. He knew if he went, he couldn’t quit halfway through.

“You have to remind yourself why you left in the first place,” Kelly said. “If you want out of the trip, you’re probably going to be back working in an office.”

Once he made the decision to go, Kelly continued to work for another year and a half saving up money. When the time felt right, he quit his job as a computer systems administrator for a nonprofit and embarked on the nearly two-yearlong journey.

When Kelly arrived in Alaska in July 2009, after the summer solstice, there were almost 24 hours of daylight. From there, he biked straight to Fairbanks, Ala., roughly 1,000 miles away.

“I packed pretty much everything I’d need until I got to Fairbanks,” he said. “I had food, a stove, sleeping bag, tent, stuff for warm weather and stuff for cold weather. My bike has four saddle bags, and it all fit.”

Kelly was far from alone on the road. Other cyclists also made the journey, and he would occasionally meet up with some and they rode for a few days together. Bikers kept in contact through email on the way down to Argentina, warning one another about conditions ahead on different trails, he said.

“People have been doing this [trip] for a few decades now,” Kelly said. “I would say, based on my calculation, roughly a few dozen [people] leave each year for the trip. Several months of my [journey] were spent with other people.”

For the first part of the trip spent in Alaska, Canada and the lower 48 states, Kelly camped at night in remote areas. In Canada, he said people can camp anywhere; it’s part of the culture. With the exception of bears, Kelly said staying in the middle of nowhere is less dangerous than city dwellers think.

“I feel safer out in the middle of nowhere,” he said. “You run into less people and those you do are a lot more respectful. I think people forget how awful big cities are sometimes.”

Greg McCausland, a teacher from Binghamton, N. Y., also made the journey at the same time as Kelly. The two rode together in Mexico and then again while crossing the Panama Canal. Despite what some Americans might think, McCausland said the U.S. is actually one of the most dangerous places to bike.

“Because of the volume and speed of traffic, and the fact people aren’t very tolerant of bicycles, it’s not always safe,” he said. “In most places in Latin America, people are on bikes, horses or just walking. Drivers are much more tolerant there.”

Pan-American Highway travelers generally take breaks in towns or cities along the way, Kelly said, ranging from a few days to a month. Because the landscape changes every day, familiarity can be comforting, he added.

“Always being in a new town and a new place, you’re [constantly] in transition,” Kelly said. “Sometimes you just want something steady and familiar, so I’d stay in a town and go to the same bakery every morning. By that time, you know the owner there, and you feel like you belong somewhere. But you have to keep moving.”

South America proved to be a more difficult segment of the trip. Obstacles like the Atacama Desert, the world’s driest place, the steamy jungles of the Amazon and the flat, windy plains of Patagonia stand in cyclists’ way.

John Vogel, who arrived in Ushuaia the same day as Kelly with his wife and two sons, said there were days without a house.

“Sometimes we had to scrounge for places to stay,” Vogel said. “We would go to a fire station, an army base or a school and ask them if we could stay. Sometimes people knew we were in a predicament and they’d let us stay with them.”

Despite the hardships, McCausland said deciding to go on the journey changed his life.

“After six months, things start to change,” he said. “You get really accustomed to it, and you adjust to the fact you can do anything you want and see anything you want. It’s incredibly liberating.”

On arriving in Ushuaimi, Kelly said it was a bittersweet moment. While he missed the freedom of traveling different continents by his feet, he had missed friends and family back home, and Chicago’s food selection.

“The food on the trip was good, but sometimes, it got a little repetitive,” he said. “When you’re in the Peruvian mountains, you’re only going to be eating so many different kinds of food. You start to realize Chicago has such a wide variety of cultures represented.”