Letting forest fires burn, or even intentionally setting them, has often been considered good forest management. But that policy has become problematic as more and more people build homes in forested areas.

Now, some innovators have come up with a new way to clear and renew America's woodlands.

A massive tree-eating machine called the feller buncher is used to thin out trees on the Trinchera Blanca Ranch in Colorado, CBS News correspondent Barry Petersen reports. The goal is creating a sustainable forest.

A sustainable forest is more fire resilient, said Ty Ryland, who grew up on the ranch and has managed it for almost three decades.

"A forest fire isn't always bad, as long as it's a cool burning fire. You know, we do some prescribed burning, and we'll do more prescribed burning in the future," he said. "But when we get these big, devastating crown fires that we've seen from California all the way through the West into Colorado, those are extremely devastating. And we're trying to prevent ... those big, catastrophic fires."

There are heroic efforts to put out the fires before they destroy the growing number of houses built in forested areas, but that undercuts nature's way of burning off undergrowth. And that is making forests dangerously dense.

At Colorado's Kiowa Creek Ranch, owned by the Audubon Society, an area has been cleared to look like it was for centuries: trees widely spaced where the worst threat is a grass fire. And for that, the ponderosa pine trees have a nature-made defense.

"What's great about these trees in particular, ponderosa pine, is they're fire adapted. They develop a thick bark at their base that is fire resistant," said Jonas Feinstein, Colorado's state conservation forester.

But biologist Ty Woodward sees danger in the dense forest nearby.

"When you see that, do you say to yourself, 'I gotta get rid of that stuff or it's going to come and get me someday?'" Peterson asked.

"Absolutely," Woodward said. "And then you have no forest left and you just have a dead zone of black trees."

At Trinchera Blanca Ranch, thinning creates its own problem: what to do with all the excess trees, including thousands of acres killed by mountain pine beetles.

So Blanca Forestry Products was born. The sprawling lumber mill produces about 20 million board feet of lumber a year sold across two dozen states. And what helps manage the forest comes with about 70 jobs that help people up and down the rural valley.

"It's a great boost for the economy. Helps everybody, helps the people working here, helps the small businesses. You know, there's a lot of money that's staying here and people staying here," said John Medina, a night watchman at the mill.

The strategy works, but it is expensive, Ryland said.

"It's not so much a moneymaking enterprise. We're trying to break even," he said. "The ownership is dedicated to make this happen. So, you know, it is an investment."

"So this is really an emotional investment. It's not really a capitalist investment?" Peterson asked.

"Absolutely, it's an emotional investment," Ryland said.

The investor is billionaire financier and environmental philanthropist Louis Bacon. Trinchera is one of several areas he is working to preserve — like a once-overgrown aspen grove that was cut down and is now regrowing.

"It's going to be denser than what you see in the parts that we don't harvest. But that density will start to reduce, there'll be some that die out. The animals will have some effect on some of them. So it will thin itself as we go on," Ryland said.