BIWABIK, MN (KDAL) - A couple of big snow-centered races are celebrating their 29th years this weekend. The John Beargrease Sled Dog Marathon kicks off Sunday in Duluth and the Pepsi Challenge cross country ski race at Giants Ridge is going on today. Ski race officials said the conditions couldn't be better, with a solid 8-inch snow base and a freshly-groomed course. There are five races today, starting with a 48K and a 24K Classic at 9 a.m., followed by the freestyle equivalents at 9:30. The 10K started at 9:45. An awards ceremony will follow at 2 p.m.