Up to 2,500 men and women with handlebar moustaches, deerstalkers and full tweed regalia will cross icy rivers, scramble steep scree slopes and battle through dense forest from dawn til dusk as they compete in the 2010 Mighty Deerstalker, the most outlandish trail running event in the British calendar.

Such is the popularity of the adventure run, which takes place near Innerleithen in the Scottish Borders, that entry numbers have quadrupled in only four years.

Alongside the lung busting ascents, intrepid athletes will also be faced with a series of challenging obstacles from start to finish. 

In the past the tests of both nerve and courage have included the straw bale wall, the ice cold 'Big Pond' with super-suction mud, the log balance bars, prickly tunnels, slippery tree-lined banks, cargo nets, a flooded tunnel (The Sump) and an arena-style assault course.

At The Deerstalker fancy dress is naturally de rigeur, and prizes are awarded for the best country attire. 

The fashion Police have NOT been invited so organisers expect everything from plus-fours, Deerstalker caps or antlers, full cravat-and-sports-jacket ensemble, moustache, pipe and monocle to Lycra, skin tight and very inappropriate shorts and brightly coloured knee length socks.

Since 2007 The Mighty Deerstalker concept has been a winning formula for organisers Detail Events and their partners Scottish Borders Council and EventScotland. 

Jim Mee, Managing Director of Detail Events, organisers of the Mighty Deerstalker, said: “By launching the adventure-style, challenging and fun-fuelled format of the Deerstalker in 2007, we knew we could tempt runners of all ages and abilities away from the comfort of the road and into the rugged and evocative landscape of the Tweed Valley.

“The response has been incredible with entry numbers growing significantly year on year.  From 600 runners in 2007 to an expected 2500 elite athletes, weekend warriors and first time have-a-go heroes ready for a bit of mud, sweat and beers in 2010, we know we have created the winning formula for our participants.'

The event takes place in the evening following a day of merry-making in the grounds of the beautiful Traquair House, Scotland's oldest continually inhabited house.

With local food and drink, music and a programme of entertainment in the event village for both athletes, supporters, spectators and families, the Deerstalker has a very sociable atmosphere all of its own.

To savour the flavour of this superlatively wacky event; or to grow antlers and front up to the big, bad and just-a-little-bit-surreal trail run with bite log onto www.themightydeerstalker.com