Runner on the decent of Snowdon in the Snowdonia Trail Ultra Marathon wit Clogwyn du'r Arddu in the background.

The Original Snowdonia Ultra Marathon Eryri

Trail Running | Snowdonia Trail Marathon Eryri 2027

Snowdonia Trail Marathon Eryri 2027 Trail Running Ultra Marathon

The Ultra Trail Marathon Eryri is an epic mountain running journey through the heart of Eryri (Snowdonia), combining high mountain terrain with spectacular valleys, forests, and remote trails.

Starting and finishing in Llanberis, the 56km route packs in around 2,300m of climbing and takes runners high onto the slopes of Yr Wyddfa (Snowdon) before continuing on a much bigger journey through the surrounding mountains and valleys. Expect long climbs, technical trails, fast descents, and constantly changing terrain, with some of the most spectacular scenery in North Wales accompanying you along the way.

Redesigned for 2027, the course retains the wild character and serious mountain challenge that have always defined the Ultra, while allowing greater opportunities for runner support and event management throughout the route.

This is a proper mountain ultra: tough, spectacular, and immensely rewarding. After a huge journey through Eryri, the finish back in Llanberis promises to feel very well earned.

The Ultra Marathon is a UTMB-Indexed race and will earn finishers 3 ITRA points.

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Route Maps
Route Description
Prices
Important Information

Dates

11 Jul 2027

Location

Llanberis

Distances

Ultra Marathon

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Routes

Run - TBC

Route Description

The Ultra Trail Marathon Eryri is the biggest journey of the weekend, linking the high mountains around Yr Wyddfa with valleys, forests, remote trails, and one of North Wales' most remarkable historic landscapes.

Starting in Llanberis, there is little time to settle in before the course heads towards the mountains. Runners climb high onto Yr Wyddfa early in the race, reaching close to 1,000m above sea level and earning immense views across the surrounding peaks and valleys.

But this is only the beginning.

From the high mountain, the route drops away into a much broader journey through Eryri. The terrain constantly changes as runners move between mountain paths, quieter tracks, wooded sections and valley trails, travelling far beyond Llanberis before eventually turning north for the long journey home.

At around 47km, tired legs are rewarded with another dramatic change of scenery as the route enters Dinorwig Quarry, part of the Slate Landscape of Northwest Wales UNESCO World Heritage Site. The historic quarry workings create a spectacular setting for the later stages of the Ultra, with vast slate landscapes sitting beneath the mountains that have dominated the day's journey.

Emerging from Dinorwig, the finish is getting closer, but there is still work to be done as the route makes its final approach towards Llanberis. Eventually, runners descend towards the event village and a finish line that will feel very well earned.

At approximately 56km with around 2,300m of ascent, this is a demanding mountain ultra rather than simply a longer trail race. The redesigned course retains the scale, wild scenery and sense of adventure that define running in Eryri, while allowing greater opportunities for event support and course management along the way.

From the high slopes of Yr Wyddfa to the historic slate landscape of Dinorwig, this is a full day of mountain running and an unforgettable journey through Eryri.

Pricing

Tier 1 Price

Ends: 13/09/2026

£96.99 UK Athletics Affiliated
£98.99 Non-affiliated
Instalments Available Until 1/4/27

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Tier 2 Price

Ends: 31/12/2026

£99.99 UK Athletics Affiliated
£101.99 Non-affiliated
Instalments Available Until 1/4/27

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Tier 3 Price

Ends: 04/07/2027

£101.99 UK Athletics Affiliated
£103.99 Non-affiliated
Instalments Available Until 1/4/27

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Tier 4 Price

Ends: 08/07/2027

£106.99 UK Athletics Affiliated
£108.99 Non-affiliated

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Important Information

Minimum Age

You must be at least 20 years old to take part in this race.

Registration

If you opted for a postal entry, there is no need to register in person before the event. Your Final Instructions will be emailed to you, and they will also be available on the website 10 days before the race.

If your bib is not being posted, you will need to collect it from registration. Registration will take place on Saturday and before the race on Sunday morning. We will confirm specific times in your Final Instructions.

Registration is usually located at the event village in Llanberis, situated next to the Community Centre - LL55 4UR

Start Time

The Ultra Trail Marathon usually starts at 05:00, though this is subject to change. The race start time will be confirmed in your Final Instructions, which are available to view on the website 10 days before the race.

Cut Off Times

There are staged cut-offs across the race to ensure the safety and well-being of volunteers and competitors.

21.8km (marathon/ultra split #1) in 4 hours 40 minutes. You will be directed to continue on the marathon course if you arrive after this time.
28km (Beddgelert feed station) in 6 hours.
38.5km (Bron y Fedw feed station) in 8 hours.
45.3km in 9 hours and 15 minutes. You will be directed onto the marathon course if you arrive here later than this.
Finish line timing will end after 11 hours and 30 minutes.

Prizes

We hold a prize-giving ceremony after the racing; approximate timings will be detailed in the Final Instructions; however, it is a good idea to listen out for information on any updates that come in over the tannoy. Sometimes the ceremony may be delayed, and we wouldn't want you to miss out. We don't send out prizes after the event, so make sure you attend the ceremony and receive your big Welsh cheer!

Prize Categories for the Snowdonia Ultra Trail Marathon are (for both men and women)

Overall: Top 3*

Senior: 1st runner

V40: 1st runner

V50: 1st runner

V60: 1st runner

V70: 1st runner

All prizes must be collected on the day.

* If any runner places in Overall and Vet, then a drop-down system will occur.

Mandatory Kit

All competitors must carry the mandatory kit listed below. This kit is for your safety due to the often unpredictable and quickly changing mountain conditions and the isolated nature of the route.

Spot checks will be in place, and anybody found without the required kit will not be allowed to race.

Waterproof jacket and trousers - with taped seams and an integrated attached hood.
Suitable off-road running shoes - fell/trail shoes
Hat and gloves (head and hand cover)
Whistle
Emergency food
Foil blanket
Drinking water
Mobile telephone
Reusable race cup or bottle