For nearly 25 years, Tompkins and her late husband, Doug, have worked to protect in excess of 2.2 million acres of land creating national parks across Chile and Argentina.
"Between our family foundations
we concentrated on land conservation, land restoration, species restoration and re-wilding, which has become a major part of our work," Tompkins tells CNN.
It's not just the scale of their conservation efforts
that impresses, it's the variety -- from near impenetrable rainforests in the south to wetlands in the north.
"We work in the Valdivian rainforest and have protected just under 800,000 acres so far, and then the Patagonia Park project which is steppe grasslands," she explains.
"Then up in the northeast of Argentina we have the Ibera Wetlands
which is subtropical and a gold mine in terms of biodiversity.
"So each of the main parks are very different landscapes and I love them all."
Call of the wild
Tompkins always had a passion for the outdoors -- she grew up on a ranch in California -- but the turning point in her life came when she started working for Yvon Chouinard, who founded the outdoor clothing company Patagonia
"Working with Yvon and his wife, and being a climber and skier, you begin to see that the natural world you took for granted was not as it seemed -- things were really beginning to break down," says Tompkins.
By the 1980s, Patagonia was funding environmental projects -- donating 10% of pre-tax profits and to this day channels 1% of revenue -- with the "1% For The Planet"
scheme -- towards nonprofit environmental groups. More than $70 million in cash has been raised to date.
Tompkins spent several years as CEO of Patagonia before stepping down in 1993. She remains on the board and very much on board with its mission.
"I'm very proud of the Chouinard family who own the company and the company itself. They are moving the needle on what it means to be a good business."
Upon leaving the business world, Tompkins married Doug -- founder of The North Face and Esprit -- and moved to Chile where the pair began to implement their shared vision of conservation.
Their arrival and subsequent land purchases proved controversial in the early years -- locals, perhaps inevitably, suspicious of their motives.
"Opposition largely came from the early years in Chile," Tompkins says. "Like anything, actions speak louder than words and it was very difficult to imagine that a couple would arrive in Chile, buy up big chunks of land and not cut the trees down -- especially in the case of (Chile's largest private nature reserve) Pumalin Park
Over time, any hostility has dampened, although conspiracies would continue to circulate -- the idea that the couple were secretly setting up a Zionist enclave
being one of the more fanciful rumors.
On the contrary, the Tompkins were keen to put their business acumen to good use.
"You are very concerned about the economics of a project and how do they dovetail with creating an industry of tourism," Tompkins explains.
"We work very hard on that, because we believe that healthy communities -- economics and local pride -- are a consequence of conservation. So those things are very important."
The governments of Chile and Argentina have also played their part, helping to ensure that Tompkins' original land purchases earmarked for conservation have been doubled. The aim is eventually to create up to 15 million acres of new national parks.
After the tragic loss of husband Doug -- who died in a kayaking accident in 2015 -- Tompkins is tasked with completing the job they started together.
"He was the visionary for a lot of this work. When you look back on what we've done it was pretty audacious to think two individuals and their teams could take on a project of this scale and work with governments in this way."
Tompkins' faith in governments is limited though and her enthusiastic tone changes as she contemplates the future of the wider natural world.
"I see no sign that people are really taking the truly necessary steps to thwart climate change," she replies when asked about the prospects of action at the upcoming climate change talks
"If you just look at the net losses every day -- hectares destroyed vs. hectares protected -- I think the figure would be quite out of whack. Generally speaking, if you look at the oceans and the terrestrial side it's a race, and we're losing."
She counters by saying that many people do take the threat of climate change seriously, but without government intervention these efforts are futile.
"The fact is it's sovereign legislation that makes the biggest hit -- without that you can forget it.
"Nothing is going to happen until there are massive crises and that people have no choice but to change. Until then, I don't have any hope to tell you the truth. It's not a very cheery point of view but that's how I see it."
Tompkins despondency is countered by a burning desire to finish the work she started with Doug.
"A civil society -- that's what I'm shooting for. A society that has a relationship with the non-human world that represents more of a truce between the two and that human communities have dignified and healthy lives.
"I'm a fighter by trade. For me it's a moral issue, an ethical issue that we whom have been given so much need to use your talent and your resources to try to change the things that you believe are at the heart of this inequality for the human and non-human world."