The American Birkebeiner (or Birkie) is the longest cross country ski race in North America. The 51 km race from Cable to Hayward, Wisconsin is a member race of the Worldloppet Ski Federation, a federation which includes the world's most famous cross country ski marathons such as Sweden's Vasaloppet and Norway's Birkebeinerrennet.
Started in 1973, the Birkie is one of a few races worldwide named after and commemorating a historical episode from 1206 in which a group of Birkebeiners - soldiers who fought for Sverre Sigurdsson and his descendants in the Norwegian civil war - smuggled the illegitimate son of Norway's King Håkon Sverresson from Lillehammer to safety in Trondheim. At Birkebeinerrennet in Norway, skiers still carry packs symbolizing the weight of a 18 month old child; this tradition, although not required, is also respected by some skiers of the American Birkebeiner.
The Birkie has a reputation of attracting skiers of various ability levels. Cross country skiing is particularly popular in Wisconsin, Minnesota, and the Upper Peninsula of Michigan, and the Birkie draws a large number of skiers from this area who otherwise ski only recreationally. In addition to the Birkebeiner itself, the race day includes the shorter Kortelopet, a race geared more toward recreational skiers. All told, each year the race is attended by over 5,000 skiers and about 20,000 spectators.