(CBS News) The National Park Service is announcing that a 30-acre piece of private land in Utah's Zion National Park will not be developed. That's welcome news for conservationists, as a growing number of private homes are being built in some of these protected areas.
Our national parks have been called "America's best idea," places untouched by time. Nearly 300 million people visit America's national parks each year.
People don't think of the parks as places where you could build a vacation home. But people are now erecting McMansions in the middle of some of the most pristine places in the United States.
Hank and Mariangela Pino Landau built a vacation rental home on private land inside of Utah's Zion National Park six years ago.
Hank Landau said, "It's pretty incredible to be living in a place that's surrounded by this beauty that is unplugged from the matrix of life."
With a front yard that overlooks the iconic Tabernacle Dome, it's hard to blame them for wanting to live here. Yet many of the park's visitors, such as Russell Arnold do: "They don't belong inside a park like this. If you wanted to see that kind of stuff, we can stay home."
Asked what he says to critics, Hank Landau said, "This is private land. Do you want me to tell you to take your private property and sell it to your neighbor? Our neighbor is the park."
There are 11,640 pieces of private land inside U.S. national parks. From Yosemite to Yellowstone, many have homes either built or being built on them. The land was owned before the national parks existed or ended up inside them as the parks expanded, according to the National Park Service.
Will Rogers, president of The Trust for Public Land, asked how big of an issue this is, he said, "It's a really big deal. It's like putting a fast food chain in the middle of the National Mall."
He's particularly concerned about what critics call a "McMansion" being built on a bluff overlooking a valley in Zion. Julie Hamilton was shocked to see it during a hike. "All of a sudden there's this big house up on hill," she said. "It's like, are they going to build more? What's happening here?"
What's happening is budget cuts. In the 1960s, Congress established the Land and Water Conservation Fund -- $900 million a year paid for with offshore drilling royalties from oil companies. That money was historically used to buy up private lands in national parks when landowners decide to sell. But two-thirds of the oil money is now routinely spent by Congress on other programs, leaving the parks unable to compete with wealthy buyers.
Rogers said, "There are more and more people with the means to have two and three and four homes. And even if they're only using them for a few weeks a year, they like to have them in iconic landscapes."
Yet some members of Congress blame the Park Service for wasting money expanding park boundaries, instead of buying up the land inside them.
Just three percent of National Park land is privately owned -- most of it is still vast open space. But the fear is that private land could be subdivided and some day you could look down a valley and see a neighborhood.
Actor Robert Redford has been an outspoken advocate of preserving the national parks ever since he shot "Butch Cassidy and the Sundance Kid" in Zion in the '60s. He worries the government no longer has the funds to protect the parks from more development.
"Once you start something, it's kind of hard to bring it back," he said. "The national parks here in this country are some of the greatest places on earth. Let's at least leave something for our future generations, so they don't have to see this either on a film or in photos, they can see it with their own eyes."
Without government funds, Rogers' organization had to find a private donor who bought land for sale at the base of Tabernacle Dome. Dozens of homes could have been built, but the land will now be gifted to the Park Service.
Rogers said, "Had that not happened, we might see a McMansion going up on this property here at Tabernacle Dome."
Just up the road, the Landaus say they built their house to fit into the landscape, not as a trophy home.
Asked if they've been picked on, Mariangela Pino Landau said, "We've both been hurt by some of the things that have been said that have been disparaging about us being here and us having no right to be here."
Hank Landau added, "The park had opportunities to buy land around here and haven't had the money to do so."
This year, Congress has allocated $161 million to the parks for buying land as it comes up for sale, but the price tag of the priority properties they are trying to protect is more than $2 billion, according to the Park Service.
Watch Ben Tracy's report in the video above.