The federation was founded on 10 June 1978 in Uppsala, Sweden.
[1] Membership in Wordloppet is limited to one race per country, with an emphasis being placed on prestige.
While primarily concentrated in Europe, there also races in North America, Asia, and Australasia.
Actual racing distances may vary from year to year according to the local snow conditions, but usually, there are different categories: full distance (at least 42 km, the length of a non-skiing marathon (26 miles)) and shorter ones for children and less experienced skiers.
For Vasaloppet, the oldest of the races, the full distance is about 90 km (56 mi).