Ulsrudvann Rundt 3. lop is a race in a low-key running series around Ulsrudvann in Oslo's Ostmarka area. The route is a 2,870-meter trail race, with start and finish on the gravel road between Haralokka and Ostmarksetra, a short distance from the Ostmarksetra parking. Runners sign in and collect bibs at the start before the evening start; the organizer notes a queue can form close to closing time.
The course leaves the gravel road, follows the recreational path near Ostmarksetra, and then loops around Ulsrudvann on trails that are partly demanding and worn. Red and white markers show the way at important trail junctions. First-timers are advised to run the course beforehand, and both GPX and Strava versions are available. If the field is large, the race may be split into separate male/boy and female/girl starts a few minutes apart. Results and the all-time list are usually updated the same evening on the organizer's site, with results also posted through Kondis.