At the eastern edge of the Grand Canyon, well beyond the tourists who crowd along the South Rim, sagebrush desert stretches for miles, almost untouched except by wild horses or the livestock of Navajo herdsmen. Below, the turquoise water of the Little Colorado River flows into the larger and darker Colorado, their courses merging within the burnt sienna walls of the canyon. The confluence is considered sacred to some Native Americans—and awe-inspiring to others fortunate enough to visit the remote spot.

"Every time I go, I think about my place in the universe," says R. Lamar Whitmer, a Scottsdale, Arizona, developer. "When you look at God or the creator's handiwork, you can't help but feel special or that you are part of something."

That's why Whitmer says he wants to make this special part of the Grand Canyon accessible to the world. He and his partners are working with the Navajo Nation to build the Grand Canyon Escalade, a billion-dollar development with hotels, restaurants, shops, and a Navajo cultural center on the desolate canyon rim, almost 30 miles from the closest highway.

View Images VIRGINIA W. MASON, NG STAFF. SOURCE: NATIONAL PARK SERVICE

Tourists who may not otherwise be able to visit the floor of the canyon could ride a gondola to the confluence a mile below. There they would stroll on an elevated walkway and take in the stunning view from stadium-style seating.

"In a world hungry for harmony and beauty, can you think of a better place than the Grand Canyon?" Whitmer asks.

The plan, now pending before the Navajo Nation Council, has caused division on the reservation and with other tribes, including the Hopi, who say the canyon, and the confluence in particular, are sacred and should not be disturbed.

It has also caused alarm in the National Park Service and among conservationists, who warn that the proposed development—along with another commercial project at the park's main entrance on the South Rim—could alter the canyon forever.

The controversy raises prickly questions about the nature of sacred spaces, how best to protect natural wonders like the Grand Canyon, and who should have access to, and profit from, public lands.

View Images Visitors look into the Grand Canyon from Hopi Point on the South Rim, in this image from 1955. Photograph by Justin Locke, National Geographic

A Place Revered but Vulnerable

"The Grand Canyon is a place that people come to be awed by Mother Nature's work over millions of years," said Grand Canyon National Park Superintendent David Uberuaga, who calls the threats facing the park the gravest in its 95-year history.

"It is a World Heritage site, one of the Seven Wonders of the World—and that is not a place that needs additional development. It is not a place to be entertained, but a place to come to connect to creation and this experience."

Carved by the Colorado River over millions of years, the Grand Canyon has been occupied by humans for more than 10,000 years. It plays an important role in the creation stories and religious practices of several Native American tribes who now have reservation land near the canyon, along its rim, or on its floor.

"The Grand Canyon is our spiritual home," explains Leigh Kuwanwisiwma, director of the Hopi Cultural Preservation Office. "It is the point of our emergence. It is also our final spiritual resting place."

The canyon was protected as a Forest Reserve in 1893, and it became a national park in 1919. President Theodore Roosevelt famously implored that the canyon be left forever in its natural condition. "You cannot improve on it," he said in 1903. "The ages have been at work on it, and man can only mar it."

View Images Concentrating on their handiwork, Hopi Indians in May 1937 weave baskets in a community near the Grand Canyon. Photograph by Michael Ledger, Getty

The number of visitors has swelled a hundredfold since its inception as a national park, to about 4.5 million visitors a year—a number Uberuaga says is straining the park's capacity. There have been constant efforts to commercialize it, industrialize its resources, and pilfer its archaeological treasures. Stewards have struggled to protect it while sharing it with the world.

Today the threats to the canyon's future are "real and ongoing," Uberuaga says. Despite a 2012 ban on new uranium mines on a million acres of public land around the park, the canyon's waterways are still at risk of pollution from grandfathered mines and those on nearby state land, he says.

Meanwhile, the wilderness experience on the canyon floor, where the park limits river trips to 25,000 individuals a year, is being disrupted in some parts by noise overhead. An estimated 300,000 flights annually now cross over the canyon, Uberuaga says.

Air traffic could increase even more with proposals to expand the state of Arizona's Grand Canyon Airport and flights at the Hualapai Tribe's Grand Canyon West. The seven-year-old development on the west side of the canyon, home of the popular glass Skywalk attraction, became accessible to tourists by a paved road in early August. Up to a thousand people a day take helicopter trips to Hualapai land in the canyon, then embark on short boat trips on the river, Uberuaga says.

But the planned developments to the south and on Navajo land to the east are raising the most concern because of their scale and location.

View Images Employees in 1949 perform the "sing away" ceremony, a popular farewell to visitors leaving the Grand Canyon Lodge, on the North Rim. Photograph by NPS, EDEN

Grand Plans for Gateway Community

At the South Rim of the canyon, outside the main entrance of Grand Canyon National Park, sits Tusayan, Arizona, a modest collection of hotels, restaurants, gifts shops, and a National Geographic IMAX theater. For the past two decades the Stilo Development Group, backed by Italian investors, has sought to build out the gateway community but has been thwarted by a variety of obstacles.

After county voters nixed a proposed project, Stilo became the "driving force" behind a 2010 campaign to incorporate the town, town manager Will Wright explained in a phone interview. The strategy worked, and soon after incorporation, the town approved Stilo's plans to build some three million square feet of commercial space with luxury hotels, upscale shops, spas, a dude ranch, and more than 2,000 homes.

Town leaders foresee many benefits of the project, including 20 or more acres they will get to build affordable housing for tourism workers. "It's an opportunity to establish a community where you have residents who can sink roots and take a more active role," Wright says.

Opponents worry about a sustainable water source, and whether a town incorporated to facilitate growth will apply appropriate scrutiny.

"This isn't about housing," counters Alicyn Gitlin, coordinator for the Sierra Club's Grand Canyon protection campaign. "This is about a very large scale, commercial development going in adjacent to the national park." The Sierra Club is pushing a proposal to protect 1.7 million acres of the area around the park as a national monument.

"People come to the region to get a sense of place of the desert landscape in which the Grand Canyon is situated," Gitlin says. "All of these things are industrialization of the landscape around this park. They are impacts occurring on a scale that wasn't predicted when these parks were created."

View Images The glass floor of the Skywalk gives visitors a unique view of the Grand Canyon. The site is managed by the Hualapai Tribe. Photograph by John Burcham, National Geographic Creative

Weighing Gains and Losses

Back on the east side of the canyon, the proposed Grand Canyon Escalade project—the largest ever tourism venture by the Navajo Nation—promises to create 2,000 jobs on-site and as many as 1,500 indirectly. That on a reservation struggling with high unemployment and pockets of desperate poverty, says Deswood Tome, special adviser to Navajo Nation President Ben Shelly, who is backing the project.

The area around the remote site is so undeveloped that most residents don't have running water or electricity. The dire conditions are due to the Bennett Freeze, a ban on development imposed during a land dispute with the Hopi that lasted more than 40 years. Congress officially lifted the freeze in 2009.

View Images Protesters in 1966 hold signs to show their opposition to the proposed building of two dams in the Grand Canyon. They succeeded in blocking construction. Photograph by Arthur Schatz, The LIFE Picture Collection via Getty

That's when Whitmer says he reached out to former Navajo Nation President Albert Hale (now a state representative) and other partners to build a tourist development there. The Navajo, who are being asked to invest $65 million for a road and other infrastructure, would earn 8 to 18 percent of receipts, Whitmer says. The tribe stands to make $40 million to $70 million annually, Tome says. If the Navajo Nation Council approves the development agreements in the next several months, the 420-acre Escalade could open by May 2018—in time for the national park's centennial.

"If the National Park Service and the Hualapai Tribe and other entities are making a profit off the Grand Canyon, who are they to say the Navajo Nation cannot do that?" Tome asks.

The tribe and the park service disagree over who controls the land by the river where the lower part of the project is planned. The Navajo say their reservation starts at the river, while the park service claims its boundary goes a quarter mile up. Uberuaga says the park service would use its jurisdiction to stop development there. The Navajo Nation will exert its sovereignty, Tome says. "We're not going to acquiesce to the National Park Service whatsoever."

The project is also likely to be challenged by the Hopi, Kuwanwisiwma says. The Hopi Salt Trail runs along the Little Colorado River by the confluence and onto the sipapuni, or place of emergence, upstream.

View Images A Navajo looks out over the land on his return to his reservation home. Photograph by Maggie Steber, National Geographic Creative

Although Whitmer and Tome insist that the project avoids all designated sacred sites that require protection, the project has caused a divide among the Navajo people. Some families who historically resided in the area, along with their supporters, have formed a vocal opposition. And some candidates challenging Shelly for the nation's presidency in an August 26 primary election have come out against Escalade too.

Renae Yellowhorse, part of the Save the Confluence group, says the pristine area where clan stories say life began is the wrong place for development. Her elderly relatives who live in the area worry, "Where are our prayers going to go?"

"It's not for an outsider to tell me what is sacred," Yellowhorse says. "I say it is sacred because I go out there and pray and give my offerings, not because it is on some map or written in some book."