FLAGSTAFF, Ariz. - To those who know and love the Grand Canyon, the names of its historic lodges are synonymous with the national park itself.

Phantom Ranch, Bright Angel Lodge, El Tovar - all bring to mind a place coveted worldwide for its sweeping views, river rapids and history told though layers of geology.

But the fate of those names is up for debate after a longtime Grand Canyon concessionaire applied to trademark them.

Approval of its bid would mean Xanterra Parks & Resorts could charge future concessionaires to use roughly 20 names of the park's most popular properties. It also could walk away with those names, leaving the iconic lodges and other facilities to adopt new identities.

The National Park Service is weighing how to respond with the U.S. Patent and Trademark Office on the matter, which a spokesman described as relatively uncharted territory.

Park Service spokesman Jeff Olson said he's aware of only two other national parks where companies have registered for trademarks for names - Yosemite in California and Hot Springs in Arkansas.

"This is a new issue for us," Olson wrote in an email.

Xanterra applied for the trademarks just before its contract to manage South Rim hotels, restaurants and mule rides expired at the end of December. It later won a temporary contract and can bid on a new one expected sometime this year.

The Greenwood Village, Colorado-based company and its predecessors have operated at the Grand Canyon for more than a century. Places like the famed El Tovar Hotel, which overlooks the canyon, were housing visitors before the Grand Canyon became a national monument and, later, a national park.

Experts say the intent of the trademark applications is clear: to stifle competition for the upcoming concessions contract or earn money for the value Xanterra has created in the names.

"They're just playing a card," said Kristelia Garcia, an associate professor at the University of Colorado Law School.

Xanterra declined to comment.

The National Park Service wouldn't say whether it would oppose Xanterra's trademark applications. But going forward, the agency says it will include language in contracts that tells concessionaires how names and logos associated with the park can be used.

A recent change to a contract proposal at Yosemite National Park reflected that with hundreds of names of park identifiers.

Yosemite concessionaire Delaware North Companies Parks & Resorts placed the value of its intellectual property - including trademarks it bought in 1993 for names like The Ahwahnee Hotel and Curry Village - at $51 million.

The Park Service said the value of the well-known lodge and cabin names is closer to $3.5 million. But future concessionaires aren't required to pay it. A successor instead could choose to rename those places, the agency said in the contract proposal. Bidding on it ended last week.

Derrick Crandall, counsel at the National Park Hospitality Association, said park concessionaires have invested time and money to create brands and market them to the public, building up goodwill in the names. It's not unlike what happens with hotels and businesses outside national parks, he said.

"If the next concessionaire decides, 'I don't want to pay that intellectual property,' and they want a new name, that's fine," Crandall said. "It's legitimate to say there's some kind of payment due."

Doug Sylvester, dean of Arizona State University's Sandra Day O'Connor College of Law, said Xanterra has a good case for winning approval for the federal trademarks but suggested the Park Service oppose the move so it could include the right by any concessionaire to use those names as part of a contract.

"To lose those names is to devalue those particular operations," he said. "I do think for those who are familiar with the Grand Canyon, those names themselves have some value."

For the public, the effect could be its attachment to names that have been staples of the Grand Canyon for decades. El Tovar - named after a Spanish conquistador who never made it to the Grand Canyon - harkens back to a railroad company that set up lodging for passengers amid a remarkable landscape. Bright Angel Lodge pays ode to the popular hiking trail and winding creek of the same name.

Wayne Ranney's first Arizona residence was at Phantom Ranch where he worked as a backcountry ranger. He says he couldn't imagine the grouping of rustic cabins, cantina and cottonwood trees being called anything else.

Phantom Ranch is nestled deep within the park and is reachable only by foot, mule or raft.

Famed architect Mary Jane Coulter designed it in the 1920s with materials from the surrounding landscape. She rejected efforts to name it Roosevelt's Chalets.

"We'll all get used to a new name if it comes to that, but how far down on the mat will these companies go to squeeze every nickel out of it?" Ranney said. "This is a heritage that belongs to all of us. To strip it of its name is to take a piece of it away with you."