Natalie Jablonski / WXPR News

The American Birkebeiner is well known for its difficulty and impressive distance: a course more than 30 miles long that takes hours to complete. 

But Birkie weekend hosts other events, including one that celebrates the Nordic roots of cross country skiing: the second annual Nikkerbeiner race on wooden skis.

On the streets of downtown Hayward, it’s easy to spot the Nikkerbeiner skiers among the fray.  They’re the ones wearing woolen knickers, knee socks, and an occasional Vikingish helmet.