Elver Park trails open to Birkie skiers February 22, 2021 9:11 PM Shelby Evans Updated: MADISON, Wis. — A virtual version of the State’s largest nordic ski race is happening this week and Elver Park is open for skiers to participate. The American Birkebeiner happens annually in Cable, Wisconsin. This year to safely accommodate the average 40,000 participants and spectators, the organizers are offering a virtual version, where skiers can self report their times from all over the country. Elver Park is one of the national virtual venue partners to the Birkie. Organizers measured out a route that would match the 46 kilometer trail length in Cable.