Lier Backyard Ultra takes place in Årkvisla, Buskerud, in late August. Runners complete trail laps repeatedly until the race challenges their endurance and resolve. The primary event is an ultra marathon, set at 80.4 km. A separate 4 km race is also offered for those who prefer the location without the extended backyard format.
The short race includes youth categories. Adult participants are divided into 5-year age groups. This structure caters to club runners and local amateurs alongside experienced ultra runners. Sportsklubben Kraft organizes the main ultra. The event is in its second edition, according to available race notes. Past results indicate a small but competitive field, with club affiliations like Seig IL, IL Koll, Sturla Ultra, Bamford 1869, and Løpeglede frequently appearing at the front.