SACO (AP) – Nearly seven decades after it began showing movies, the nation’s second-oldest drive-in theater is in danger of falling victim to escalating real estate values.

The Saco Drive-in sits on a stretch of busy U.S. 1 that has become crowded with car dealerships and other businesses. The property already attracts frequent offers from would-be buyers, and its value is expected to soar when sewer lines are extended close to the site to serve a nearby development.

Drive-in manager Richard Roberge, who has leased the 15-acre property from his brother Barney for eight years, says he’s not sure how long the theater will remain in operation.

“If it were to become a mall tomorrow, or a business industrial park, it’s nothing I’d be in favor of,” he said. “But I have no say. It belongs to my younger brother.”

Barney Roberge, a Biddeford developer, did not return phone calls seeking comment.

Opening in 1939 as the Saco Open Air Auto Theatre, the Saco Drive-in was the first of its kind constructed in Maine. The only others still operating in the state are in Skowhegan, Westbrook, Bridgton and Madawaska.

The nation’s oldest operating drive-in, in Orefield, Pa., predates the Saco Drive-in by a year.

Construction of drive-ins peaked during the mid 1950s, when there were 39 of them in Maine and close to 5,000 around the country. Today, only about 400 remain.

Many of them went dark as the value of their real estate exceeded what they could earn as seasonal theaters. Built on the rural outskirts of cities, they got caught up in waves of development over the ensuing decades as the cities sprawled outward.

During their decline, drive-ins acquired an unsavory reputation as many owners began screening slasher movies and pornography in an attempt to compete with multiscreen theaters at the mall.

The number of drive-ins has stabilized over the last decade. The survivors have repositioned themselves as family-friendly entertainment, offering a mix of nostalgia, novelty and value. The Saco Drive-in charges $13 for one car and up to two people and $3 for each additional passenger.

“There’s absolutely no place else you can take seven kids to the movies for $28,” said Dennis O’Connor, a New Hampshire resident who likes to load his car with children while staying at a campground in Biddeford. He goes to the drive-in about six times a summer.

The theater is quiet most of the year, but in summer only thick fog stops the nightly shows. So one rainy night last week, Richard Roberge was collecting money at the gate and dispensing advice to the occasional customer on everything from tuning their radios to ordering at the snack bar.

“We have the best chili dogs on the East Coast,” he told more than one driver. “I’m not bragging on ’em, it’s just the way it is.”