Doug is careful to note that technically he does not own Pumalin or the other parks. They are controlled by nonprofit foundations, although Doug and Kris control the foundations.
Doug has learned to understand the anxiety his projects have created.
"You can well imagine that it seems weird," he said of the reaction in Chile, "because there is no real tradition of philanthropy. There is no real tradition of conservation. Their focus in the last 18 years prior to our arriving was on a dictatorship where human rights were of great concern, not the environment."
He said, "One thing you should really know is all of this opposition has been fantastic for our working, our themes of conservation environmentalism. It made us public figures. They've given us a microphone we could have never had before."
The Tompkinses' parks have been attacked repeatedly here and in Argentina, but the latest crisis in Pumalin may be the most serious yet: a new push to connect the national highway.
Chile is a long, narrow country, and Pumalin sits in the narrowest part of the country, crossing its entire width from the Argentine border to the ocean and literally cutting Chile in two.
The problem: The national highway -- actually a dirt road -- literally ends where Pumalin begins. It's a rough, rocky 50-mile ferry ride around Pumalin. The only other option is to drive into neighboring Argentina and back. Which is why now there is enormous pressure to push a road right through the heart of Pumalin.
Carving the highway through the Andes would cost hundreds of millions of dollars; it would require snowy mountain passes and tunnels miles long, perhaps a hundred miles of driving to cross 50 miles of park. Yet in this very poor, very remote region of this developing country it has become a question of national sovereignty for some.
Leading the charge is the member of Chile's parliament for the region, Claudio Alvarado, who is pushing for a special debate on Pumalin in the National Assembly in April.
"The reality is that we need to integrate Chileans south of Pumalin into the rest of the country. They shouldn't have to go into another country to get to another city in their own country," Alvarado said.
Alvarado is pushing to expropriate a large swath of Pumalin for the road and for massive power lines. "As Chileans we are not against protecting the environment," Alvarado said. "We just want preservation of the environment to be compatible with the development of our country."
"Mr. Tompkins lives in a reality very different from the one that most Chileans live in. He has been very successful in life. He chose to devote the rest of his life to preserve the environment. But his philosophy in my opinion is extreme, to the point that nothing can be touched or nothing can be changed."
Doug and Kris bristle at the idea of a road and power lines in Pumalin. He is proposing what he says is a more cost-effective coastal route that would take advantage of some little-traveled roads and require two high-speed ferries to jump the deep water of the fjords.
Preserving Pumalin has become an obsession for the Tompkinses. Doug never tires of the magnificent landscape that has become his life's work.
At age 63, he feels a sense of urgency to his task. From the air he points to the magnificent Renihue Valley, with a glorious lake fed by glaciers. He would like to believe it will remain like this forever.