Snowdon 100 Mile Ultra

GB Ultra Presents The Yr Wyddfa (Snowdon) 100 Mile Ultra Marathon

Get ready to push your endurance to the limit with the return of the epic Yr Wyddfa Ultra 100, spanning a breathtaking 102 miles through the rugged peaks and valleys of Snowdonia National Park. With a massive 5,788m of elevation gain, this is one of the most demanding ultramarathons in the UK, a true test of physical and mental resilience.

A Bold Adventure Through Eryri’s Majestic Terrain

Traverse some of Wales’ most iconic landscapes as you journey across Snowdonia Eryri, tackling steep climbs, remote trails, and awe-inspiring scenery. This self-navigated race includes strategically placed checkpoints and full GB Ultras support, with live GPS tracking via GB Race Tracker so friends and family can follow your progress in real time.

Your Ultra Journey Starts Here

Think you've got what it takes? Entry to the Yr Wyddfa Ultra 100 is by application only, ensuring runners meet the necessary qualifying standards. Once approved, you can secure your place today, with flexible payment options available via PayPal, ClearPay, or Payl8r (subject to status), making it easier to commit to this unforgettable experience.

Qualifying Criteria

Participants must be at least 20 years of age on race day, in accordance with UK Athletics Trail Running regulations (Rule T3 (141) S5).

To ensure safety and preparedness, applicants must be in good physical condition and have completed ultramarathon events of 50 miles or longer, ideally with experience navigating mountainous terrain. All submitted experience will be assessed individually during the application review process.

You may include upcoming races as part of your experience, provided they are expected to be successfully completed before the start of the Yr Wyddfa Ultra.

As this is a self-navigated mountain race, all entrants must demonstrate the ability to read and interpret maps competently. While GPS devices can be used, participants must not rely solely on technology and should be confident using a map and compass, especially in challenging conditions such as low visibility, rough weather, and night-time hours.

For full details please visit the official GB Ultra race website.