Plans to introduce Eurasian Lynx just 30 miles from Glasgow, 1,300 years after it became extinct in the UK, have been outlined in a consultation paper.
For the past year, Lynx UK Trust have been in discussions with landowners about a trial reintroduction of lynx in Argyll and Inverness-shire.
The trust also recently submitted plans to Natural England for a similar pilot at Kielder Forest in Northumberland.
The plan has been opposed by some who fear the cats would attack livestock.
The trust said Lynx could bring benefits to the ecology of the areas by controlling deer populations and helping to protect the ailing capercaillie.
NFU Scotland and the Scottish Crofting Federation have strongly criticised the plan.
Dr Paul O'Donoghue, of Lynx UK Trust, said over-population of deer in Scotland was damaging forest habitats and restricting forest regeneration.
He said an "exploding" pine martin population was having a negative impact of the capercaillie population, by eating the eggs of the bird.
"This is a classic example of the negative impacts that come with removing species like the lynx from an ecosystem," he said.
He said Lynx were also noted for controlling deer by influencing behaviour, by keeping herds moving through the forest, spreading out their browsing sustainably.
Similarly, lynx presence around pine martens should influence them to spend less time on the forest floor where they find capercaillie nests, he said.
An area of 10,000 sq miles of land has been identified for the proposed pilot, which Lynx UK Trust could "comfortably be home for 250 lynx".
The area would stretch from Loch Lomond and the Trossachs into the West Highlands.
Consultation has already begun with several landowners in the region including Ewen Maclean, a member of the Maclean family which owns and manages the Ardgour estate, which covers 30,000 acres and is on the western edge of the potential lynx habitat.
Mr Maclean said: "We're very supportive of any effort to rebalance the natural environment.
"I think this is something that can bring a huge benefit to our forests and add to the fantastic eco-tourism offering already in the region."
Mr O'Donoghue said "We're hugely excited to explore the idea of further lynx trial reintroductions here with the local community.
"Imagine how amazing it would be to hop on a bus in Glasgow and be in lynx habitat half an hour later.''
But NFU Scotland said the past two years have seen a "long line of brazen and presumptuous claims about the imminent reintroduction of lynx to the UK".
Deputy director of policy Andrew Bauer said: "This is a far more complex matter than those pressing for the release of lynx would have anyone believe.
"On the forest edge, there will be significant predation of ewes and lambs and no amount of warm words and reassurances will convince any farmer or crofter otherwise.
"We have used various forums and meetings with key stakeholders, officials and politicians to express our grave concerns, not only about the implications of the proposed reintroduction for livestock keepers, but also the tenor of the public debate.
"In our opinion, no local consensus nor political consensus has ever been secured and this supposed 'consultation' will not change that."
Russell Smith, of the Scottish Crofting Federation, said: "We have always been resolutely opposed to the reintroduction of anything which is going to damage sheep farming."