Yr Wyddfa Ultra 100
Betws-y-Coed, United Kingdom • 5-7 Sep 2026
Yr Wyddfa Snowdon Ultra 100
The Yr Wyddfa Snowdon Ultra 100 is a 102 mile mountain ultramarathon in Snowdonia (Eryri) National Park. The course has approximately 5172 m of elevation and 250 places. The event in 2026 is scheduled for Saturday 5th September and has an overall cut-off of 42 hours. Live online GPS tracking is used and the race is classed as a self-navigation event.
Course, checkpoints and support
The route leaves Betws-y-Coed and passes along the Snowdonia Slate Trail into Nant Gwynant valley, past Sygun Copper Mine, Llyn Dinas and Llyn Gwynant on the way to Beddgelert. There are 11 checkpoints spaced along the route. Checkpoints provide refreshments, hot food at indoor locations, and medical or first responder cover. Some checkpoints do not permit support crews; other checkpoints allow limited support with parking restrictions. Support crews are restricted to one vehicle per runner and no more than two crew members at a checkpoint at once.
Entry rules, safety and kit
Entrants must be at least 20 years old and have previous ultramarathon and mountain experience. Runners must be competent map readers and not solely reliant on GPS navigation. Mandatory kit must be carried at all times and includes a hardcopy map, compass, waterproof coat and trousers, headtorch and backup light, thermal/survival bag, water (min 1 litre), emergency rations (min 500 calories), whistle, and a GPS tracker supplied at registration. One pacer is permitted from Checkpoint 6; pacers must be on foot, self-sufficient and carry the mandatory kit. Visit the organization's website for the most recent information.