Paul Brennan, the Prudential Douglas Elliman broker who has the listing, says the property is zoned residential and could be divided into six single-family lots. Or a deep-pocketed buyer could snatch up the entire airport and have a personal landing strip steps from the beach, along with views of Block Island Sound. Alas, he’d have to ditch the Gulfstream IV for a single- or twin-engine Cessna.

“It’s not a huge runway,” Mr. Brennan said of the airport, which doesn’t have a control tower and is mostly used by residents and aviation enthusiasts. “You are not going to land big jets.” Nor is there enough room for a “fly-in, fly-out community,” with personal hangars as well as garages connected to each residence. The eight shareholders who own the airport “made a decision that they would like to sell it either as an airport or a residential subdivision,” he said.

The act of selling alone has built-in obstacles. For one thing, buyers looking to convert the property to residential use would have a wait on their hands. According to Arlene Salac, a spokeswoman for the Federal Aviation Administration, any airport that takes federal funding “agrees to grant assurances” and “keep it as an airport for the public’s use” for 10 years beyond the date of the last grant issued. In this case, that would be 2019 — as the airport has received more than $1 million in grants, in increments, since 2002. (The grants were used for upgrades like taxiway edge lights, an automated weather observing system and a runway guidance system.) Also, the F.A.A. must approve the sale.

Reached by phone, one of the shareholders, Perry B. Duryea III, declined to comment. It was Mr. Duryea’s father, Perry B. Duryea Jr., a speaker of the New York State Assembly and a pilot, who bought the airport property in 1957. He died in 2004.

Rudy Weisse, the airport’s assistant manager, says about 10 aircraft, mostly single- and twin-engine, take off and land at the Island’s easternmost airport on weekdays; on weekends the number jumps to 35 or 45, including helicopters, which ferry day-trippers to and from the beach. Fifteen planes are based at the facility, which is not set up to dispense fuel or service the planes.

The listing has made a lot of people curious, Mr. Brennan said. “Everybody is trying to figure out what they can do with it.” Whatever that may eventually be, there is hardly a need to worry about neighbors. The airport is virtually surrounded by 1,000 acres of county parkland.

Mr. Brennan acknowledged that there are a number of people who want to see the airport remain in use for flights, in some form. If, for instance, Route 27 flooded along the Napeague stretch and Montauk got cut off in a hurricane, the airport could be used to bring in supplies.

“I would hate to see it go residential, or someone might try and change it to commercial,” Mr. Brennan said. The airport represents “a way of life, like the farms, like the commercial fishing. It’s another East End life support that is going to change.”

Peter Lowenstein, the president of the 25-member Montauk Pilots Association, flies his six-seat single-engine Bonanza to the Bahamas and the Caribbean in winter and to Montauk in the spring, summer and fall. “In a perfect world,” Mr. Lowenstein said, “I would love for the airport not to get sold and remain the way it is. If it is sold, most of the pilots feel they would like it to remain a public-use airport.”

Mr. Lowenstein described the property as “not desirable land,” with “major shrubbery and dunes” that require pilots to “land high and drop in on the airport.” The beach is at the northeast end of the runway; to the other side of it along East Lake Drive are a few businesses and marinas on Lake Montauk. In Mr. Lowenstein’s “wildest fantasy,” he said, “some guy with more money than brains wants to build his own private airport.”

Gary DePersia, a broker at the Corcoran Group, saw things differently, describing the site as “a niche property” and a “great spot” that could generate “great interest.” Wondering how many houses would have water views from the second floor, he said, “There is a substantial value for it as lots either for a developer or user, or spec homes,” or as a private airstrip. Montauk has “some very high-end people,” many of whom may have planes, who keep their yachts in Montauk harbor even if they live in Bridgehampton or Southampton. “Maybe someone wants to get there quicker and doesn’t want to go to a public place.”

Before Mr. Brennan officially listed the airport, he approached town, county and state officials, on the theory that it was a “community asset that would be missed if lost.” But Fred W. Thiele Jr., a state assemblyman, expressed doubt that the state, the county or the Town of East Hampton would be interested in taking over operations. He saw it as more likely that a group of pilots might be interested in maintaining or acquiring the site.

In an e-mail message, Vanessa B. Streeter, a spokeswoman for the Suffolk County executive, Steve Bellone, was also doubtful about a county takeover, saying that with a current $300 million deficit, “it would not be financially prudent for Suffolk County to consider the purchase of the Montauk Airport.”

Jay Schneiderman, a Suffolk County legislator, said that although he would like to see the airport remain in service, the county already owns and operates Francis S. Gabreski Airport in Westhampton.

He also pointed out that while the town-owned East Hampton airport, the only other such facility in the area, is “constantly controversial” largely because of jet and helicopter noise, Montauk’s airport has “broad community support” for remaining “the little airport that it is.” With only small planes and very few homes nearby, “this is an airport that everyone seems to love.”