The Mattoni Liberec Trail Run takes runners from Liberec into the Jizera Mountains, concluding the RunCzech season. This trail race offers two distances, 12 km and 22 km, with the shorter option still featuring hills. The event attracts over 3,400 participants, and its main races sell out, giving it the atmosphere of a major event.
The course crosses forests, skirts a reservoir, passes through a granite quarry, and returns to the hills overlooking the city. The 22 km route includes the dam and additional ascents in the Jizera Mountains. Key points of interest are the Liberec Zoo, the Forest Swimming Pool, Bedrichov Reservoir, and vistas towards Jested Mountain. A DM family mile and a DM bambini run are also part of the day's activities, extending the event beyond the primary trail races.