A passport-stamping system for cyclists, like the one used on New Zealand's Otago Central Rail Trail, has been designed to promote the proposed Federation Rail Trail.
Rail Trails for NSW was in Balldale last year to push for activation of the trail there, and will now step up advocacy to fully link Holbrook with Rutherglen.
Chairman John Moore contacted the Rutherglen Men's Shed last month about building a red wooden box that would allow riders to "self-stamp".
"It [the cycle passport] has never been done before in any part of Australia," he said.
"The lady with the Otago Rail Trail in New Zealand was only too happy to help and send some passports for show and tell.
"We believe from all our experience this will be a real boon."
Burrumbuttock cyclist Marion Vile tested out the prototype - designed to look like an old signal box - for a group gathered on Monday for the launch.
"We ride the Murray to Mountains Rail Trail often," she said.
"It would be great to connect it up with Holbrook."
Her hypothetical ride went through Holbrook, Morven, Culcairn, Walla, Burrumbuttock, Brocklesby, Balldale, Hopefield, Corowa, Wahgunyah and Rutherglen.
If that infrastructure was built, and linked up with Murray to Mountains, Mr Moore says it would be Australia's longest rail trail route, at 235 kilometres.
The Brisbane Valley rail trail is 161 kilometres, while the Great Victorian Rail Trail from Tallarook to Mansfield is 120 kilometres.
Mr Moore plans to meet with the Federation and Greater Hume councils about the idea.
"We would like to get the towns like Burrumbuttock and Brocklesby built up and people staying overnight there," he said.
"It would be the first rail trail to cross a border."
Rail Trails for NSW is a non-for-profit run by volunteers and has advocated for the Tumbarumba to Rosewood route, which will open in April.
Deputy Chairman Tim Coen said the $5 million pilot project was made possible through an amendment to existing legislation and his group was pushing to streamline that process.
"What we're aiming to do is to get legislation passed to lift the rails," he said.
"The best thing to do for a sustainable rail trail is to lift the rail and the sleepers - which can be sold to held underwrite the building of the trail - but keep it in parts where there is historical value, and use the old foundations.
"The NSW Parliament passed the legislation for Tumbarumba virtually unanimously, to officially close the line and lift the rail.
"There's an understanding this is for local communities' benefit."
Mr Coen said landowners and councils in Federation and Greater Hume would have to be on board to make the Federation Rail Trail a reality.
"The idea is not to make farmer's lives harder, far from it, but yes there will have to be gates and fences and consideration of those types of things," he said.
"We would need a governance structure."
Modelling done by La Trobe University in 2009 on the Murray to Mountains Rail Trail shows what a new link could bring to the region, Mr Coen said.
"They found day trippers will spend $50, and overnight visitors $250," he said.
"Those are conservative figures.
"Where we are standing [in Rutherglen] got 16,600 users in 2009, and if only 10,000 of those did from here to Holbrook, that would still yield $1.1 million.
"There is so much pent-up demand for rail trails; I know people riding in New Zealand at the moment, who have done Victoria and want to go elsewhere, but they can't do NSW.
"We can get those people here.
"Towns are well-distributed along the way, at distances of about 20 kilometres, the gradient is wonderfully mild - it's very doable."
IN OTHER NEWS:
Rail Trails for NSW will continue to advocate for the project, and in the meantime Destination Rutherglen chairman Greg Duncan will keep the "Rutherglen" passport-stamp box for cyclists.
"What this will do is connect us all - our stretch of rail trail, to NSW," he said.
"We need to make sure this trail connects fully with Murray to Mountains.
"It's absolutely fabulous NSW is catching up quickly to Victoria."