Oslo Bergen Trail is an ultra-trail race from Oslo to Bergen. The main contest is for teams consisting of 2 or 3 persons. This is an adventure race conducted in self anatomy, to receive support is not allowed. The route is approximately 500 km long and has 16000 meters elevation gain/loss. The route follows the marked trails of the DNT (Norwegian Trekking Association) wherever possible and practical. In some areas the route traverses forest and mountain terrain without path or along a very tiny path. The route is in general not marked, and each team is responsible for their navigation. On the way to Bergen you will experience the typical lowland forest landscape in the eastern part of South Norway, before entering into a gentle mountain landscape (Norefjell, Hardangervidda) and passing close to the glacier Hardangerjøkulen. In the west the mountain landscape becomes more rough, intersected by fascinating valleys and fjords, and the paths (if any) are tiny. The weather can be anything from 30 degrees and blue sky to zero degrees with wind, rain and snow. Of course, the backpack must have equipment to handle any such conditions. The maximum time is 224 hours.

Contests for individuals are organized on the partial distances Oslo-Noresund 100K and Oslo-Vasstulan 200K.