Olney Theatre Center for the Arts marked the opening of an important chapter in its history yesterday, with the first performance in the troupe's new, larger and high-tech theater.

While the new theater looks to the future, Olney is also celebrating the past with the choice of a classic American play, William Gibson's "The Miracle Worker," as its first show in the space.

The mixing of old and new reflects the design of the venue, with a state-of-the-art facility inside and a traditional, Shaker-inspired exterior that blends with the older, rustic buildings on the center's Olney-Sandy Spring Road campus. The grand opening also ends a period of significant expansion of arts facilities in Montgomery County, with several major performance houses and a host of smaller projects coming on the scene over the last couple of years.

The new theater, an $8.5 million project financed by a combination of public and private money, is about the size of the old Olney playhouse, with 429 seats arranged stadium-style on two levels. The most distant seat on the first level is less than 40 feet from the stage, and the farthest reach of the balcony is less than 60 feet. There are no obstructed views, as is the case in what is now called the "Historic Mainstage," which Olney patrons have both loved and hated over the years.

The new stage is considerably roomier than the old one, with fly space overhead for set pieces and backdrops, sizable wings and trapdoors on the stage floor. The stage lighting system is digital, and considerable attention has been given to the advanced acoustic design. The building includes multiple chandeliers, a vaulted atrium lobby, elevators, improved dressing rooms and twice as many bathrooms as the old place.

Guiding the expansion has been Olney's artistic director, Jim Petosa, who insists the focus will remain on the actors and not on "spectacle," despite the advances in staging that are now possible. "I'm not afraid of losing our identity, because we didn't tear anything down," he said. "We grew from what we had before, and we've enhanced a legacy rather than obliterated it."

The new facility is connected to the old theater in a park-like collection of buildings containing four performance spaces and enhanced living quarters for artists and actors, a unique feature of the theater. An additional $2 million is being spent on upgrades to the campus. For the entire project, Montgomery County chipped in more than $3.6 million, and the state government contributed almost $5 million.

The year-round, multifaceted center is a vastly different place from the primitive summer theater that opened 67 years ago. "This is certainly the end of a long chapter," Petosa said. "I think the first time we even took pen to napkin and actually drew out some idea of what this campus might look like was back in 1987. And at that point, there was no scene shop, no rehearsal hall or even a lobby on the front of the old building. It was a rapidly deteriorating summer place that didn't even have heating."

With the recent purchase of an additional four acres of adjacent land, long-range plans call for the construction of an inn and a restaurant "to support the revenue stream," as Petosa put it.

Petosa, 50, began directing plays at Olney in 1979 and became producing director in 1989 and artistic director in 1993. He has seen the theater emerge from provincial status to earn a regional reputation.

Now dividing his time between the Olney campus and Boston University, where he is director of the School of Theatre, he has forged a working relationship between the two institutions that he hopes will lead to wider recognition for the theater company. Education is an important component of the Olney experience; the National Players, a touring group founded in 1949, is a program of the theater center and visits high schools and colleges around the country.

With government coffers flush with cash in the 1990s, and money readily available from private sources that were enjoying a booming economy, Montgomery County began an unprecedented expansion of artistic facilities that has recently culminated in the opening of new performing spaces for Round House Theatre in Bethesda and Silver Spring, a new home for the nationally recognized Imagination Stage for children in Bethesda, the renovation and expansion of an old theater into an East Coast center for the American Film Institute, and the opening of the BlackRock Center for the Arts in Germantown and the glittering new Music Center at Strathmore, a performance and education facility in North Bethesda.

"I expect it will be five or 10 years before we see any significant new building," said Theresa Cameron, executive director of the Montgomery County Arts and Humanities Council. "But we have a growing population in the upper reaches of the county, and we're going to need additional venues, especially multiuse spaces that can be used by a variety of organizations."

Cameron, who said she believes the Gaithersburg, Rockville and Damascus areas will be able to support substantial theater and music facilities in a few years, said she appreciates the way the new Olney facility blends into its surroundings and hopes the company will make its Historic Mainstage available to groups needing performance space.

Petosa has had to master the intricacies of architecture and dealing with the bureaucracy of what he calls "this very regulated county" to make his dream theater become reality. Now comes the hard part: keeping those plush new seats filled. "Attracting an audience in this day and age is not easy for anyone," he said. "It's one of the most challenging tasks any American theater has to grapple with. There's no easy way of doing it."

"The Miracle Worker" continues through September 11 at Olney Theatre Center for the Arts, 2001 Olney-Sandy Spring Road, Olney. Showtimes are 7:30 p.m. Tuesdays and Sundays and 8 p.m. Wednesdays through Saturdays. There are 2 p.m. matinees Saturday and Sunday, and on Sept. 1 and 8. For tickets or information, call 301-924-3400 or visit www.olneytheatre.org.

A traditional, Shaker-inspired exterior for the new theater blends with the older, rustic buildings on the center's Olney-Sandy Spring Road campus. With 429 seats, the new theater is about the same size as the old Olney playhouse but has no obstructed views.