How far would you walk to help a mate?

Twelve special forces soldiers will spend August on the march, tramping 1600 kilometres from Brisbane to the far western town of Birdsville to raise $500,000 for wounded and war-weary comrades-in-arms.

The troop's oldest member will be a retired SAS veteran of 74; its youngest a serving soldier in his twenties. They'll head west from Anzac Square, the home of Brisbane's eternal flame, on August 3.

They will spend 33 days on the move, walking in relay and camping in convoy in a journey that will take them through Toowoomba, Dalby, Roma, Charleville and a clutch of one-pub outposts, en route to Birdsville.

The mega-walk is an initiative of Wandering Warriors, a foundation established by the Special Air Service Association's Queensland branch to raise money for services the military and Department of Veterans Affairs are unable to provide.

The SAS Regiment comprises a small, elite fraction of Australia's armed forces. Established in 1957, it operates under the motto "Who Dares Wins".

In the past 15 years the regiment has had multiple deployments to a steady stream of hotspots, including Afghanistan, Iraq, East Timor and the Solomon Islands.

Thirty-nine Australians have died in Afghanistan and 253 wounded in action since 2001; around half of them from special forces. SAS soldiers Mark Donaldson and Ben Roberts-Smith received the Victoria Cross, Australia's highest award for gallantry, for acts of battlefield valiance while serving there.

Extended absences – tours of duty can last up to 12 months and many SAS soldiers spend nine months of the year away – can place a strain on relationships at home.

Wandering Warriors executive officer Quentin Masson, a former squadron commander and 19-year veteran who left the SAS in 2011, says wear and tear on families is inevitable.

“The unit has been on constant operations for many years now, and whilst that's what they're happy to do, it does take a toll,” Masson says.

Some of the funds raised by the walk will go towards a respite program dubbed Project Excalibur. SAS soldiers in need of down-time are sent with their families for a two-week break to the Gold Coast or Sunshine Coast.

The president of the SAS Association in Queensland, Alan Bowen, says it's respite – time for a family to reconnect away from the home environment – and not a junket.

It's an intervention that can “save a guy and his career, save a family and a marriage and perhaps save a life”, Bowen says.

Other monies will be earmarked for charities that help injured SAS soldiers rebuild their lives and assist the families of those who have been killed in action.

The Departments of Defence and Veterans Affairs offers support but the famously tight-knit SAS community likes to look after its own, Masson says.

Assistance provided by charities such as the Commando Welfare League and Soldier On includes paying children's' school fees and providing additional support in the home for disabled veterans.

“There's an extra dimension of care that we can provide and that's the gap, “ Masson says.

“We don't want to be constrained by budgets or entitlements.”

While the bulk of funds raised are expected to come from corporate sponsors, the troop is anticipating the occasional whip-round, as well as a warm welcome, as they tramp west.

“The support we've got from the communities along the way has been unbelievable,” Bowen says.

Several towns have offered to open their community centres and showgrounds to the walkers, who are in line for a hearty dose of bush hospitality, along with a place to pitch camp.

The pub at Morven, 665km west of Brisbane, population 276, is preparing to roll out the red carpet.

“The hotelier there has already said he's more than happy to put a jug on the bar to collect money for us,” Bowen says.

“He can put on a barbecue, he can organise a band to play, he can organise all the people round the district to be in the pub to come and say hello and he'll give us 10 per cent of the bar till.

“It will be a big social event. It's been like that all the way through.”

The walk's end will coincide with the start of the Birdsville Races; an annual event which sees the outback town's population swell from 100 to 6000.

To make a donation, go to the Wandering Warriors website.