The Serpent Trail 100k Ultra Marathon

The Serpent Trail is a 100k long-distance trail through some of the most breathtaking countryside in the South East of ancient woodlands, greensand ridges and protected heath in the South Downs National Park.  

This is the Ultra Marathon running race along all of this stunning trail, from Haslemere to Petersfield!

The bigger climbs and more regular ascents (including the highest point in the National Park, Blackdown) come in the first half of the race with some long downhill sections, with the route then flatter for the last 30km.  The trail is a mix of tracks, paths and short sections of road on generally sandy trails that dry well.  

The whole route is permanently waymarked and check by ourselves throughout the year, but is then supplemented with regular signage throughout for the race weekend so you can just run and follow the signage rather than having to navigate and find your way!

  • 100k / 1785m Total ascent

  • Coach Transport to race start - INCLUDED in entry fee

  • 9 Checkpoints / Aid Stations

  • Highest point in South Downs National Park, Blackdown

  • UTMB Index qualifying race

  • Free TRIBE bar to collect at registration

  • 1 Drop bag at 50k

  • Pacers allowed from 50k

  • Support crews allowed

  • Fully marked with permanent Serpent Trail long distance path signage PLUS extra race signage throughout

  • Camping available on Friday and Saturday night, with Kids race on Friday!

  • Food and licensed bar in venue

  • FREE Professionally shot race images for you via our Race Photos page and social media

  • The top 3 Male and Female finishers will receive sought-after laser etched trophies!

  • FREE un-timed Kids race of circa 1km at 7pm on Friday evening, all welcome!

The 100k Serpent Trail Ultra Marathon Race has been planned so you can go fast and light, and is fully signed to allow you to just run!  Often firm underfoot due to the nature of the sandy soil, with good signage and support, relatively small hills and a flatter second half; this 100k could be fast…

Venue - Petersfield Rugby Club (PRFC), Hampshire, GU31 4EP

Race Start - 6am Saturday 5th July 2025.  Briefing 5am.  Bus Departs PRFC at 5.20 am prompt

Cut Off - 18 hours - Allowing for just under a 17.5 min mile avge.  This will be enforced at Checkpoints 4, 6 & 7 with transport back to the finish for those missing the cut off time.

100k Information page HERE

Provided - 9 Checkpoints with food and drink.    Medical cover.   Fully marked route.  Changing and Shower facilities.

Included - Coach transport from venue to start of race. Serpent Trail 100k finishers medal.  FREE professionally taken photos of the event shared on social media & available to download.

T-shirts - We have followed suit with many other events and are offering T shirts as an extra that you can purchase online at time of entry or by editing your entry at a later date. These organic cotton Tees are a small charge of £12. This is designed to ensure those getting a T shirt as part of the event actually want to have one and to try and cut down any wastage from the event.

Trees not tees - We have teamed up with Trees not tees so that you can now choose to pay for a tree being planted by them with a race entry, this can be instead of OR as well as an event T-shirt. Read all about it here and do some future good with an entry to the Serpent Trail!


We are proud to have Havant & East Hants MIND as our official charity. Mental health has affected everyone either directly or indirectly so we are pleased to be able to help raise awareness and funds to help them do their great work in supporting those in need through the event. There is the option to give the charity a donation at time of entry and we information about fundraising for them through sponsorship HERE.

By entering you agree to our privacy policy and terms and conditions. Minimum age is 18 years old.

Online entries only - ENTRIES CLOSE 9 PM Saturday 7th JUNE 2025 or when the event is full. 

This date is also the withdrawal deadline - you must have cancelled your place by this date as after this cut off point the amount of event infrastructure / logistics / supplies that have been paid for mean it is too late to be refunded. HOW TO CANCEL YOUR PLACE.

There are no deferral or substitution options. In the event of entry withdrawal there is a 75% refund until Saturday 10th May (8 weeks before the race), then 50% refund until Saturday 7th June (4 weeks before the race).  

After the 7th June 2025 there are no refunds for that years event. See our FAQ’s page for more information regarding cancelling your place and withdrawing from the event.