The final resting places of many of the country's early pioneers have long been forgotten in Western Australia's Kimberley region.

Now, a group of Perth retirees are embarking on an ambitious plan to find and mark as many of the grave sites as possible.

In their latest big lap around the Kimberley, husband and wife team Trevor and Suzie Tough installed more than 100 plaques at isolated grave sites.

Mr Tough, who founded volunteer group Outback Graves and engraves the metal plaques himself, said every grave carried a story at risk of being lost.

"It seems to be quite a nice thing to do," Mr Tough said.

"Sometimes we are putting a plaque on a grave and you think 'No one has thought of this poor fella for 80 or 100 years'.

"We research a bit and find out the stories, and the stories are just wonderful."

Mr Tough said the early settlers died from "things like measles, scurvy, malaria or snake bites".

This plaque adjacent to the original headstone is engraved with the information that Francis Tudor Shadforth, head stockman, died aged 27 after being speared on November 7, 1890. ( Supplied )

Getting help from locals

Helping the pair with the project are dozens of Kimberley locals, station managers and staff, like-minded retirees and members of four-wheel-drive clubs.

They find out the location of graves using historical research, Lonely Graves of Australia history books and local knowledge.

Sam Lovell — a member of the Stolen Generation, bushman, former stockman and tourism pioneer — helped the couple navigate over four days to a remote well at Mondooma, north-east of Derby.

Mr Tough and his wife had learnt the well contained the bodies of two men, and they wanted to place a plaque at the site.

"Sam is marvellous," Mr Tough said.

"He had not been out there since the 1960s ... we were looking for an old well, we drove within seven or eight metres of it and he pulled up just past it and said 'This well must be here somewhere' and we were right there."

Mr and Mrs Tough hope more volunteers will join them to help track down long-forgotten burial sites. ( Supplied )

Mr Tough said in the late 1880s the two men had been killed by a young man of Norwegian descent who grew up with the local Aboriginal tribe.

It is believed the man, whose skin name was Billitcha, was cast ashore from a shipwreck on an island to the north of Collier Bay when he was a child.

"He killed two prospectors on the Robinson River and then he killed another two people on Mondooma," Mr Tough said.

"One was a white fella and one was a Chinese bloke and he threw them down the well."

Mr Tough said Billitcha had been killed by tribal elders after he tried to raise "his own army of young fellas".

A plaque marks the burial site of James Webb Saddler, who died at Spring Creek Station on the Duncan Road, which weaves in and out of WA and the NT. ( Supplied )

An army of grey nomads

The Outback Graves project was hatched when Mr Tough and his old high school friend Alex Aiken met at a 50-year reunion in Perth.

Last year the pair set out on their first field trip to the Kimberley.

"We recognised once the graves physically disappear, so too do the stories," Mr Tough said.

"We all enjoy the fruits of all these people's efforts ... a lot of people went out and worked hard and a lot of them died, and it is worth recording the stories so that we do not forget that."

Because there are thousands of outback graves scattered across Australia, the pair are calling for help from people interested in becoming involved in their project.

"We really need more teams of people going out there and doing this. We cannot do it all ourselves," Mr Tough said.

"It will take 50 or 100 years to get the bulk of them marked."