Ten Tors participants prepare for the event at Okehampton. Photo: Corporal Daniel Wiepen

Thousands of young people are gearing up for the annual test of endurance and navigation across Dartmoor.

The Ten Tors Challenge takes place this weekend, with teams due in the national park to tackle the Army-organised event.

Most of the teams who enter the Ten Tors are from schools and youth groups from Bristol, Cornwall, Devon, Dorset, Gloucestershire, Somerset and Wiltshire. Scores of Scout groups, sports and ramblers’ teams and armed forces cadet units have also accepted the challenge and are taking part.

The teenagers taking on the Ten Tors Challenge will trek unaided over 35, 45 or 55 miles of some of the toughest terrain and highest peaks in southern England relying on their navigational skills and carrying all their food, water, bedding, tents and other essentials as they go.

They must complete as a team and without any help from adults and they will remain entirely self-sufficient during their arduous expeditions, including camping out overnight on the moor.

Dartmoor National Park Authority said it has been working closely with the Army and provided training to team managers to ensure that the event has minimum impact on the fabric of the moor and its wildlife.

In 2013 the national park introduced the £ for the Park scheme where those taking part in organised events on the moor are invited to make a donation enabling them to put something back into Dartmoor. Ten Tors has donated about £1,400 and this has contributed to repair work on popular access routes such as the bridleway heading south from Princetown past South Hessary Tor and Manga rails on the River Teign.

Participants in the 2015 challenge will also be invited to donate and any money raised will be spent on vital path repairs and conservation work. Teams are also invited to return to Dartmoor to help out on volunteer days, carrying out practical work to benefit Dartmoor.

Dartmoor National Park Authority rangers and voluntary wardens will be on hand throughout the weekend and the national park outreach vehicle will be at the event start to provide information to participants and their families.

Peter Harper, chairman of Dartmoor National Park Authority said: “Dartmoor National Park Authority has for many years worked closely with the organisers, landowners and commoners to minimise the environmental impact of the Ten Tors challenge and to maximise the local economic benefits of event.

“We know that the event can help foster a passion in young people to help look after this very special place, now and in the future.

“Having led a Ten Tors team myself for the past 19 years, I know how challenging six months of training and the event itself can be. The reward is seeing how the young people develop from individuals into a team to master that challenge.

“We wish all those taking part in Ten Tors and Jubilee Challenge 2015 the very best.”

The 55th Ten Tors Challenge starts at Okehampton Camp at 7am on Saturday. Immediately after the start of Ten Tors, up to 300 youngsters with special physical or educational needs, many in wheelchairs, will start the Jubilee Challenge, competing on routes up to 15 miles. The youngsters can enter either as a team or as individuals, each one accompanied by an officer cadet from Exeter University Officer Training Corps.