Oslo Trail Challenge 50km follows 50 kilometres of forest trails through the Marka wilderness north of Oslo with 1,041m of officially published D+. At an estimated 21m of D+ per kilometre the course ranks among the most runnable 50km ultras in the European trail database -- D+/km ranks 312th out of 390 (Rank 1 = most vertical) -- making this an endurance and pacing challenge rather than a climbing race. Oslo Gardermoen airport (OSL) is 24 minutes from the race start in Gjerdrum, making Oslo Trail Challenge one of the most accessible European trail races for international runners.
Public transport is excellent and Oslo city accommodation is abundant at all price points. The 50km shares the event with 100km and 200km options through the same Marka forest network. Race date: September 26, 2026. The 50km was not sold out as of mid-2026; registration typically opens in June and is confirmed at langtoglenge.org. Entry is 950 NOK (85 euros, or 1.69 euros per km). The race is ITRA-certified.