The first picture show nearly 36 years ago was a frothy first-run '40s musical. The last picture show, tonight, is a nightmarish R-rated movie about a dead child molester returned to life.

And so, the single big-screen Elkton Cinema, the last indoor movie theater in Cecil County in the northeast corner of Maryland, closes its doors for good. In this county of 60,430, the former movie palace with its ornate wall murals, is going out of business.

Multiscreen theaters and VCRs notwithstanding, the 585-seat Elkton has made money in recent years with its $2 prices and next-to-new features. But the kitchen cabinet firm next door is expanding, and even 719 signatures on a petition filed with the town's zoning board failed to save the theater.

The demise of the Elkton Cinema has hit teen-agers especially hard. In this county seat that was once the quick-marriage capital of Maryland, there are few other activities or locales catering to adolescents. Even the bowling alley bans those under 18, unless accompanied by an adult, after 6 p.m.

"Once they shut this down, this town will be nothing," said Michelle Welch, 14, on hand with 268 others Friday night to see "A Nightmare on Elm Street." In the lobby were posters of other movies a sign said were "Coming Soon," but which would not be shown here.

Said Brian Aro, 14, solemnly, "It's like taking a heart out."

About seven miles from here, Newark, Del., beckons, with its 14 indoor movie screens. But many of the young in this working-class town of 6,500 do not have the wherewithal, or the wheels, to travel there and pay the $4.50 ticket price.

Elkton retains an unpretentious small town atmosphere. A nickel will buy you an hour on the Main Street meters, and post cards left over from World War II are for sale at Stanley's Stationery. Two doors down, Your Family Restaurant is just what its name says it is.

On nearby Rte. 40, fast food outlets and a small shopping plaza share the scene with the more dated roadhouses and motor courts and the vintage Elkton Drive-In, which is closed for the season and up for sale. It may soon be replaced by houses or a shopping center.

James Simpson began in the movie business at the drive-in in 1953. For the last three years, he has managed the Elkton Theater. His wife, Rose Simpson, who works for the county planning department, spearheaded the petition drive.

Those who have worked at the theater include Mayor James G. Crouse and City Commissioner Jesse P. Boyd.

"There's not much the town could do," said Boyd. "When you have a willing buyer and a willing seller, you can't stop it."

The Elk Theater, as it was known then, opened its doors April 13, 1949, becoming the seventh indoor movie theater in the county. Before that, Elkton's New Theater had flourished in the basement of the New Central Hotel, until the city's worst fire hit Main Street in December 1947. The Elkton Armory showed films for 15 months, until brothers Everett and Douglas Connellee opened the Elk.

The front-page story in the Cecil Whig observed, "The opening of any new place of a public nature in a town the size of ours is news, but the opening of an establishment such as Elk Theatre would be news in a much more cosmopolitan atmosphere."

Boasted an advertisment, "No effort has been spared to make the Elk the finest in motion picture theaters. Imaginative planning, the untiring efforts of skilled craftsmen, and the finest of equipment have resulted in a truly magnificent theater. With modesty, but with pardonable pride, we dedicate the Elk to the public. With the sincere wish that you, your family and your friends will enjoy many hours of entertainment in this, your theater."

Admission prices were 50 cents for adults, 25 cents for children. The first film was "Take Me Out to the Ball Game," with Frank Sinatra, Esther Williams and Gene Kelly.

Jack Jamison was there.

"The place was full. I sat halfway down the aisle on the floor," he recalled. Later, he worked "for Doug and Everett," ushering, operating the concession stand, making a total of $16 for seven nights a week, he said.

Jamison, 49, was there the other night, too, this time with his son, John. They were celebrating the youth's 17th birthday. Jamison hugged Rose Simpson, who said, "We just wanted to save the theater for the teen-agers, for the families, for Elkton and Cecil County."

Before his death last year, Douglas Connellee had negotiated with Ron Creeger, who leased the theater. Creeger and Connellee's widow differ on the details, but the deal for Creeger to buy the building fell though.

Chabert & Duval Ltd., the French-owned cabinet company that adjoins the theater, offered a satisfactory price and applied for a special zoning exception to convert the Elkton Cinema into a warehouse.

On Jan. 28, the zoning board gave the go-ahead. "The board is sympathetic with the sentiments of the theater supporters," it said in its written opinion, "but finds their objection to be irrelevant . . . . "

And so it all is ending this weekend. The marquee letters have been packed in boxes, for use in another theater Creeger owns. He had tried to rent a family movie to close with, but the distributors balked and "Nightmare" was held over.

"What's the next attraction?" Rickie Maine, 14, asked his companions as the three Elkton teen-agers walked past the theater.

"Nothing; it's going down," said Scott McCloe, 13.

"Oh, no," said Robert Young, 14.

"Realistically, survival of the fittest is what this country's about," said Creeger, "and in this case, we didn't survive."