Joe Warren's life has always centered on the big screen.

As a child, he spent many evenings in playgrounds below it, more interested in the pre-movie cartoons and intermission trailers with dancing hot dogs than films. As a man, Warren focuses more on the main features as he makes his living preserving one of the true 20th-century icons.

This spring, as the drive-in theater industry celebrates its 75th year, Warren looks forward to reopening his 61-year-old Evergreen Drive-In just off Route 119 at the Scottdale exit. Evergreen is one of about 400 drive-ins that remain open today, down from the nationwide peak of 4,063 in 1958, according to the United Drive-in Theatre Owners Association, based in Middle River, Md.

Since the first drive-in opened in Camden, N.J., on June 6, 1933, the outdoor picture show has been a way of life for many Americans, especially for Warren.

"It's in his blood," says his wife, Debbie.

From 1954 to 1997, Warren's family operated Greater Pittsburgh Drive-In on Route 30 in North Versailles, where Wal-Mart is now situated.

Between 1949 and 1988, Warrens also owned the Blue Dell and Bel-Aire drive-ins, adjacent to each other, along Route 30 in North Huntingdon, Super 30 on the same highway near the Irwin Turnpike interchange, Rose on Route 130 near Harrison City and South Hills along Route 51 in Pleasant Hills. The family also owned the Super 50 Drive-In in Ballston Spa, N.Y.

Before the drive-in business, the family operated the Warren-Morocco Coal Co., a strip mining venture in Trafford. Warren says his father and grandfather sometimes ran into each other at the theater after sneaking out of work to catch the latest flick.

Their love of movies led the father and son into the growing drive-in business, where they were joined by two of Warren's uncles and an aunt. As a result, Warren and his cousins grew up at the drive-ins.

As they bought existing outdoor theaters, the family ended up in side ventures, such as the dirt track speedway at the Rose, miniature golf at Greater Pittsburgh and a diner and pool that shared the name with the Blue Dell Drive-In.

"The first memory I have of being around drive-ins was at the Super 30," Warren says.

He remembers being about 3- or 4-years-old and watching the shapes formed behind the glass block at the bottom of the ticket booth, which was backlit with neon lights that buzzed and crackled.

The gameroom of his North Huntingdon home, decorated with drive-in posters and art, is a tribute to his lifetime passion.

The focal point is the old Carbon Arc projector from the Bel-Aire Drive-In. Beside it is an illuminated ramp marker from Greater Pittsburgh listing the 5 mph speed limit and denoting when the row was full.

"The kids that used to work there were called ramp boys," Warren says. "When the row was filled, they would put on the 'full' sign."

Warren's train platform includes a drive-in, complete with cars ready to watch the show. He has a frame that includes the metal nameplates from the equipment used in the projection area.

"We have state-of-the-art surround sound," jokes Debbie, pointing to the vintage window speakers on poles positioned around the room, salvaged from the Rose and Greater Pittsburgh.

Another conversation piece is the old Jubilee hot chocolate maker, which Warren has on an end table. The Jubilee sign still rocks back and forth, just as it did at the Greater Pittsburgh Drive-In.

Warren has scrapbooks that preserve photos, ticket stubs, letterhead, payroll documents and newspaper clippings. He also has a few of the old heaters that could be rented for 25 cents to warm up the car on a chilly night.

Over 75 years, the drive-in business has remained basic -- films, projectors, screens, parking spaces, concession stands and restrooms.

"It remains pretty much the same," Warren says. "The movies change. It always keeps the business fresh."

There are minor changes. Instead of the old window speakers, the soundtrack now is broadcast on an FM frequency to car radios.

Warren has spent money on two new screens, new projector equipment, restrooms and snack bar since buying the Evergreen in 1999, a year after the season Greater Pittsburgh went dark.

Originally opened as the Ruthorn Drive-In in 1949, the theater was renamed the Evergreen the same year. When Warren bought it, the drive-in was like a throwback to the 1940s or 1950s and in need of major upgrades, according to Debbie.

"He sinks every nickel he makes into the place," she says.

As with the other Warren theaters, the Evergreen is a family business with their son, Bryan, 13, and Debbie's mother, Roberta Nese of Penn Hills, joining the couple in running the show.

Projectors once used at the Greater Pittsburgh and South Hills drive-ins still light up Warren's three screens at the Evergreen. He says the equipment was "designed to run forever flawlessly."

Despite digital technology, there's been no push to move to the format in the theater industry. He attended a drive-in association meeting that included a digital demonstration, showing the format will work.

"If and when it happens, we'll have to adapt for it," Warren says. "It's just a question of when we're going to have to put it in."

And will it be expensive to switch?

"Costly -- yeah! It's costly for us, given we're only open six months of the year."

But there is still a place for film. What most people don't realize, Warren says, is that most movie VHS tapes or DVDs they watch at home are made from the original 35mm film print.

Although the business centers on films, drive-ins feed off food.

"That's what keeps us alive," Warren says, talking about his concession stand.

The top-selling food is cheeseburgers, which Warren still makes using the chopped beef steakburger recipe his father did. Popcorn is the top-selling snack. Also popular are pizza, hot dogs and footlongs, meatball and grilled chicken sandwiches, ice cream, soft pretzels, mozzarella sticks and french fries.

The concession stand menu changes with trends, including the addition of nachos and cappuccino -- but forget wraps and other healthy choices on drive-in night. Those items just don't sell, Warren says.

Unlike other owners, Warren has resisted pressure to institute a food permit fee for those who want to bring their own food into the drive-in.

He says he tries to keep his food both quality and affordable for families.

"The families have always been the heart and soul of the drive-in business," says Warren. "It's still a date night for a lot of kids."

Warren says the future of drive-ins may eventually include being venues for big-screen pay-per-view-type sporting events.

Come March, when the weather breaks, Warren will be ready to resume his 99-hour-a-week schedule, which is truly a labor of love.

"It's almost like having a big party every night and inviting people over."