MOUNTAIN BIKING -- A fat tire event with tours for riders of all levels will debut Saturday at Fourth of July Pass trail system.

Although it's called "50 Miles at the Pass," the event's Gran Fondo format has different starting areas for rides of 10, 17, 35 and 50 miles.

Proceeds will be used by the new Lake City Trailbuilder's Association, which is working with area land managers to develop and improve trails,  said Kent Eggleston. This new association focuses on mountain bike trails but works with all user groups.

"Judging from the interest we've received, we're expecting 100 to 150 riders," said Cully Todd of Bicycle Sales and Service in Coeur d'Alene, (208) 667-8969.

Riders can find just the right amount of challenge for their style, he said, noting that the course combines the Fourth of July Pass nordic ski area on the south side of I-90 and the ATV trail system on the north side.

The 35 and 50 mile rides with be on the ATV trails, where there's some pretty good ups and downs," Todd said. "The 10 and 17 milers will be on the cross-country trails, which are tamer by comparison; more entry level."

Cost: $25-$45.

Click here for details and online registration.

Click here for course maps.