This month, more than 50 teams are set to compete in the Iditarod Trail Sled Dog Race, a 1,000-mile trek across Alaska. To gain entry, mushers must participate in three shorter qualifying races, including the Kuskokwim-300, a 300-mile competition that kicked off in southwest Alaska on January 18. Here are four entrepreneurial companies that make the race possible.

Redpaw: Food that makes dogs get up and go.

Sled dogs burn some 10,000 calories a day during races. Ken Anderson, shown here at the start of the Kusko-300, in Bethel, Alaska, feeds his team high-performance dry dog food made by Redpaw of Franklin, Wisconsin. (He carries some food on his sled and resupplies along the way.) Former biochemist Eric Morris started racing sled dogs in the 1990s while working at the University of Iowa in Iowa City. Dissatisfied with the dog food available in stores, he created his own blend, which he considered a better balance of fats and protein and an optimal mixture of vitamins, minerals, and antioxidants. After leaving his job to focus on racing, Morris met other mushers eager to buy his food and founded Redpaw in 1998. Today, the eight-person business, which outsources manufacturing to a privately owned pet food company in Wisconsin, sells its products online and in more than 300 independent pet shops in 35 U.S. states and Canada. "We promote lean muscle mass," Morris says. "If you put your dog on our food, he's going to buff up." Heavy-duty harnesses that keep dogs on course.

Anderson, who finished 13th in this year's Kusko-300, outfitted the 13 dogs on his team with Saddle Back harnesses made by of Duluth, Minnesota. The nylon harnesses, which are hooked to lines attached to Anderson's sled, feature reflective tape and padding for each dog's neck and chest. Louise Russell, a former registered nurse with a passion for sewing, opened a fabric store in Duluth in 1993 and started making rugged dog booties and other equipment for local dog-sled enthusiasts. In 2000, she changed her company's name to Today, the $500,000 business makes a full line of accessories--including booties, coats, and leg wraps--for sled dogs, search-and-rescue dogs, military dogs, and other working canines. The company has eight employees and sells products online and in specialty pet stores in the U.S., Germany, Norway, and Australia.

Trackleaders: And they're off! Tracking teams in real time online.

During the three-day race, the wind chill temperature dipped to 30 degrees below zero as 40-mile-per-hour gusts whipped the trail. Fans could track teams from the warmth of their homes, thanks to Trackleaders of Chapel Hill, North Carolina, which used data from GPS units attached to each musher's sled bag to create a real-time map of the race that could be viewed online, along with leaderboards, weather details, and other stats. The GPS units, which emit a signal every 10 minutes, also make mushers easier to find in the event of a wrong turn or accident. Mountain bikers Matthew Lee and Scott Morris co-founded Trackleaders in 2008 after testing the system during the Tour Divide, a 3,000-mile bike race from Canada to Mexico. "I was amazed at how emotionally attached people became to this little dot on the map," Lee says. Morris also founded Topo­Fusion, the Tucson company that makes the GPS mapping software used by Trackleaders. Last year, Trackleaders generated $80,000 in revenue tracking 60 events, including U.S. Army simulation exercises and biking, sailboat, and sled-dog races.

the stake Shop: Marking the trail.

To delineate the Kusko-300 course, which follows an old mail route along the Kuskokwim River, race organizers set up roughly 5,000 wooden stakes supplied by the Stake Shop of Anchorage. The 3-foot-long, 1.5-inch-wide stakes are made from Douglas fir logs shipped from Oregon and Washington and cut to size by the Stake Shop. Jerry Hagel bought the company in 1968. Today, it has four employees and supplies stakes to half a dozen sled-dog races each year, including some 15,000 for the Iditarod. The company also makes stakes for political signs and surveying equipment and does detailed woodcutting work for big-box retail stores and other large-scale construction projects in Alaska.