Chiltern Hills 100K
Chesham, United Kingdom • 9 May 2026
Chiltern Hills 100K
The Chiltern Hills 100K is a 100K ultra marathon with approximately 1800m+ of elevation. The next edition is scheduled for 9 May 2026 and the event base is Chesham Guides Headquarters in Lowndes Park, Chesham (HP5 1HX). The race is TRA licensed, held under UKA rules, listed as a UTMB World Series Index Race, and has a maximum field of 250 runners. Minimum entry age is 20.
Registration is priced at £152 (£150 for UKA affiliated runners). The event package includes chip timing with live results, GPS tracking, medical support, marked and marshalled route, a finishers medal, a drop bag at Hastoe checkpoint, event photos and a post-race meal. A withdrawal policy provides 90% credit for cancellations made more than four weeks before race day; credits are valid for two years.
Route, aid stations and requirements
The route is an anticlockwise loop that starts and finishes in Chesham and passes landmarks such as the Ashridge Estate, Ivinghoe Beacon and sections of The Ridgeway, Coombe Hill, Whiteleaf Hill, Bledlow Ridge, Great Hampden and Great Missenden. Navigation is fully marked with arrows and ribbons; runners must also carry route GPX on a watch or phone. Open GPS tracking is used during the race.
There are six checkpoints at 14km (Hastoe Village Hall), 28km (Little Gaddesden Village Hall), 41.4km (Hastoe), 57.8km (Whiteleaf Hill), 75.3km (Bledlow Ridge Village Hall) and 88km (Little Hampden); toilets are available at each. Checkpoints supply water, soft drinks, pre-mixed electrolyte drink, gels and chews, snacks, pre-made sandwiches, flapjacks and fresh fruit; hot drinks are available at roughly 44km, 60km and 75km. Mandatory kit must be carried throughout the race and includes a mobile phone with an emergency number saved, route GPX, a refillable 0.5L minimum hydration system, waterproof or windproof jacket, additional dry layers and leg cover, head torch with spare battery, warm hat/buff and gloves, basic first aid, a reusable cup, payment method (£20 cash or card) and race nutrition. Visit the organization's website for the most recent information.