Východniarska is an August ultra trail race in eastern Slovakia, organized by OZ Cassovia Trail Runners. The primary event is an 85 km race with 4,200 m of elevation gain. It starts at 9 a.m. in Kluknava and has a 22-hour cutoff at the football field in Kysak. The course is almost entirely off-road, consisting of about 90% forest trails and 10% asphalt.
The race is designed for self-reliant ultra runners, not for casual road racers. Participants must carry an emergency blanket, a charged phone, at least one liter of water, their own cup, a route map or GPS track, a headlamp, reflective gear, ID, and their race bib. A drop-bag point is located at Vyšný Klátov, approximately 56 km into the course. This is significant as many runners may still be on the course after dark. Awards are given separately for ULTRA Men and ULTRA Women. Another race listing refers to the event as the Východniarska 100, a long-distance march around Kysak.