Skiers from around the world come to Wisconsin for the race. The Birkie has a reputation for attracting skiers of varying ability levels. Olympians, national team members, and foreign professionals have competed in the event, and the Birkie also draws recreational skiers from Wisconsin, Minnesota, and the
Upper Peninsula of Michigan and countries such as neighboring Canada as well as Norway, Sweden, and other European nations. Typically almost every U.S. state is represented at the Birkie. The race weekend also includes the shorter 29 km (18 mi) Kortelopet "Korte" and Prince Haakon 15 km (9.3 mi) events. The American Birkiebeiner Ski Foundation In 2013, registration was capped at 10,000 skiers, with an additional 20,000 spectators on the sidelines cheering on the competitors. The Birkie course is quite hilly and is recognized as one of the more difficult cross country ski marathon courses in the world, despite the fact that there are several
Worldloppet events in Europe that are much longer. The current north–south alignment (used since 1992) has skiers traversing a flat section before turning onto the "Powerline Hills", a series of climbs to the mark. The trail then rolls until , when Firetower Hill takes competitors to , the high point of the race and a climb of nearly from the race start. In the early years of the race, the Birkie began with a climb up the alpine slopes of Mount Telemark, mainly as a publicity stunt, but larger field sizes made this impractical. Beyond High Point is a series of downhills, including "Bobblehead Hill" or "Sledder Hill", which has a rather tricky downhill, left turn near a snowmobile trail — allowing dozens of snowmobilers to watch and "score" skiers' falls. The trail rises steeply to the crossing of County Road OO (Referred to as "Double-Oh") which, at , is the unofficial halfway point of the race. Until 2001, the Kortelopet race ended here but was rerouted back to Telemark after splitting off from the main course at . Since 2017, the Kortelopet is and begins at OO and finishes on Main Street the day before the 50 km race. Beyond OO the course is less hilly, but by no means flat. After is the aptly named "Bitch Hill" where spectators cheer skiers up the steepest climb of the race. Several kilometers later (just south of Highway 77) the last lengthy ascents of the race---Sunset Hill & Duffy Hill---challenge tired skiers. From the top, Hayward's water tower is a most welcome sight. There are several road crossings and open fields before the skiers cross frozen
Lake Hayward. The crossing of the lake is flat, but unprotected from wind. Once off the lake, the trail twists through the outskirts of Hayward on snow trucked in for the event. Over the course of hours, thousands of tired and proud skiers make their way past three blocks of cheering spectators lining Hayward's Main Street. Warm conditions have occasionally required the finish line to be moved to a flat field just east of the lake. The race begins with several waves in order to thin skiers out along the course. Alternating skate and classical waves depart every five minutes. New skiers must ski in the last wave unless they use another ski marathon time to qualify for a higher wave. One man—Ernie St. Germaine, a former employee of the Telemark Resort, where the Birkebeiner starts every year—completed every Birkie since the first one in 1973. The 2021 Birkie was a shortened 43-kilometer race that took place over the course of February 24–28, 2021. The course was modified as well with skiers starting and finishing at the starting line in Cable, WI. The Birkie reverted to its normal Cable to Hayward format for 2022 with the new addition of an "open track" event where participants could ski the race in a more relaxed manner on the Wednesday before the main race with fewer crowds and more open trail. Despite low snow in 2024, the American Birkiebeiner Ski Foundation created a 10 km (6.2 mi) lapped course. Several races were shortened: The American Birkebeiner was shortened from 50 km (31 mi) to 30 km (18.6 mi), the Kortelopet from 29 km (18 mi) to 20 km (12.4 mi), the Prince Haakon from 15 km (9.3 mi) to 10 km (6.2 mi). The American Birkebeiner Men’s and Women’s Elite Skate race remained a 50K event. ==List of winners==