Developers and tree huggers join hands as the upscale housing market increasingly demands the latest amenity - wide-open spaces.
Paul Thomas waxes poetic about "little black dots" dropping onto the canvas of pure white snow during calving season, which he watched from his front porch. And don't get him started on the elk that graze in his "backyard." Thomas, a real-estate developer in southern California, derives the greatest pleasure from his second home in the Stock Farm Club development in Montana, watching the wildlife and drinking in the wide-open spaces. (Sure he's glad to have the golf course, too, but it doesn't do much for him in February.)

Thomas is not alone in his addiction to the "new green amen­ity." It's attracting all manner of second-home buyers who earn their share of frequent-flier miles jetting off to properties like the Stock Farm Club, Charles Schwab's private paradise in the Bitterroot Valley. Folks like Thomas are willing to pay a premium to ensure that the open spaces - and their multimillion-dollar views - remain undisturbed for perpetuity.

It's part of a growing "light on the land" trend driven by developers who are discovering that there's gold in going green, and conservationists who are finding more than a spot or two of common ground with their historical antagonists.

"I see this as a huge positive and a wave of the future," says endangered-species expert J. Michael Scott, a senior biologist with the U.S. Geological Survey and professor at the University of Idaho. Scott is buoyed by this trend because of studies that indicate more than 60 percent of federally listed endangered species are found on private, rather than public lands, making careful management of these properties critical for the species' survival.