THE NEW YORK theater scene has been bristling with doom for a while now, a situation that could be helped by lower ticket prices, sane union practices and fewer belly-button-gazing plays. But American theater viewed from the national capital is far more heartening. For those about to embark on vacation, here are some cheerful earfuls from all over:

ASHLAND, Ore., may have been unknown to many Americans when it picked up its special medallion Tony Night, but one Briton greeted it as an old friend: Ben "Gandhi" Kingsley, who started a Royal Shakespeare Company tour there years back. The Oregon Shakespearean Festival, in its 48th summer, will have 10 plays running in its three-theater complex through October.

WALL, S.D., population 700, has just opened an 1,100-seat amphitheater 60 miles east of Rapid City. Five years ago local residents began dreaming of a tourist attraction in this scenic area as home for the Badlands Western Musical Company. Backers of the Dakota Theatre Caravan's "Dakota Roads" guarantee it will run through Aug. 28, regardless of summer's so-far erratic clime.

EAST HADDAM, Conn., is home of the Goodspeed Opera House, which, although it specializes in oldies, has yet to reproduce a musical older than its stage. Producer Michael Price found "Annie," and several of his revivals have gone on to larger spaces. This year's highlight is a favorite which deserved better than it got in '49: "Miss Liberty," with a score by Irving Berlin to a book by Robert E. Sherwood, running through Sept. 16. It'll be followed by Jerome Kern's "Oh, Boy!"

CLEVELAND has restored the Ohio, a film-vaudeville palace of the '20s, now home to the Great Lakes Shakespeare Festival. Its highlight, starting July 15, after "The Merry Wives of Windsor," is the new musical "Blanco!," inspired by Shaw's prize-fighter play, "The Shewing Up of Blanco Posnet." And starting Sept. 24, a revival of last season's triumphant "Nicholas Nickleby" will be there.

NEW ORLEANS saw its old Lyric burn down in '27, but from its memories came a musical about old times in New Orleans vaudeville for the 200-seat Toulouse Theater. "One Mo' Time," now into its fifth year at the Toulouse, has gone on to New York, a national tour and productions from Sweden to Brazil to Australia. If you catch it at the French Quarter's Toulouse (Wednesday through Sunday), you also get a lobby cabaret.

MANTEO, N.C., sees resumption of "The Lost Colony," which has been playing, the war years excepted, since 1937. Its late creator, Paul Green, was saluted this spring with formation of a foundation in his name to further his philosophy of "symphonic dramas" played at the site of their historical roots. A "Colony" alumnus, Porter Van Zandt, starts still another, "Blue Jacket," at Xenia, Ohio.

MINNEAPOLIS is the set for the annual convention of the American Theater Association, Aug. 7-10. Burt Reynolds will be keynote speaker. How come? Burt's dinner theater in Jupiter, Fla., has an alliance with Florida State University, whose theater head, Richard G. Fallon, once of the University of Maryland, now heads the ATA. Wheels within wheels.

WESTPORT, Conn., besides its famed Westport Country Playhouse, notes a 35th anniversary season for Lucille Lortel's experimental White Barn Theater, which starts July 8 with "An Unexpected Evening with June Havoc, or Baby Jane Remembers." The summer's climax arrives with Maria Karnilova and George S. Irving, that couple of ballet and musicals, who long since should have been, but now will be, "Together at Last," Sept. 2-4.

SOLVANG, Calif., is 30-odd miles from Santa Maria, Calif., home base for the Pacific Conservatory of the Performing Arts, which alternates productions between its outdoor stage and its winter quarters at Hancock College. Summer bills range from "Macbeth" and "Harvey," "My Fair Lady" and "Company" to "Blood Wedding," "The Country Girl" and "Fiddler on the Roof." Watch the gypsies and their props truck down the highway not far from the Reagan ranch.

DENVER is to welcome a new director for the acting company of the Denver Center for the Performing Arts. Somewhat to his surprise, it's Donovan Marley, who cooked up the Pacific Conservatory (see above) 19 years ago. He'd expected to spend his life there, but after he had staged "The Hostage" this winter, Denver's chairman, Donald Seawell, tapped him as artistic director for the company, which has just returned from Blagoevgrad, Bulgaria, where its "Home" was staged by Howard graduate Buddy Butler.

STOCKBRIDGE, Mass., is the setting for the Berkshire Festival, surpassing the ordinary summer theaters of New England. Its casts and staff, with playwright William Gibson as an instigator, are exceptional for its actors' actors, not yet stars but those most admired by their peers. Clifford Odets' "The Big Knife" starts the summer, with "Harvey," "The Vinegar Tree" and "Fanny" to follow.

LOS ANGELES is ranked by some as the Second City of American theater, thanks, some say, to strong bookings by the Nederlander firm. Though the Nederlanders had bad luck with last summer's tryout for "A Doll's Life," they're splurging again on a new one, "Chaplin," Anthony Newley's latest effort and one of two coming musicals about the Little Tramp. The Mark Taper Forum's Rep Three is alternating "A Month in the Country" with "Richard III" through July 24.

CHICAGO, once the undisputed Second City, mostly grows its own, except for such big musicals as "Hello, Dolly!" and "The King and I," which play at the Arie Crown. Such small houses as Steppenwolf and North Light win critics' awards, as does Marriot's Lincolnshire Dinner Theater, now managed by Kary Walker, once of Maryland's Harlequin, with still another new musical about George M. Cohan, "Give My Regards to Broadway" to run through July 17.

SEATTLE has the third most Equity members and its own Equity office, thanks to the proliferation of small theaters using professionals who go from one stage to another. Active this summer is Gregory Falls' ACT--"A Contemporary Theater"--with "Crimes of the Heart," "Educating Rita," "A Soldier's Play" and "Cloud Nine" still to come through Oct. 13.

CEDAR CITY, Utah, with a bit over 7,000 souls and a Hallmark Card subsidiary 60 miles north of the Arizona border--and close on 500 miles from Salt Lake City--is home to the Utah Shakespearean Festival, which begins five productions July 14 with "Two Gentlemen." And Manti, almost in mid-state, with only 1,700 people, presents the Mormon Miracle Pageant July 14-16 and 19-23.

SAN DIEGO, Calif., finds the new Old Globe in high gear for 12 productions in its two-stage complex. Jack O'Brien (who staged the recent "Porgy and Bess") declaims against being thought of as a parking lot for TV guests; Los Angeles actors are a resource, not a requisite, he argues. Nonetheless, for "Macbeth" there will be Anthony Zerbe and for "Twelfth Night" Marsha Mason, both Old Globe vets.

PURCHASE, N.Y., which is between White Plains and Greenwich, Conn., like Wall, S.D., has been doing what President Reagan has urged: getting commercial firms to back nonprofit groups. Above the words "Summerfare '83" on signs on the state university campus is the name "Pepsico." The major theater event will be "Booth Is Back in Town," a new musical about the famed acting family, with book by actor-director Austin Pendleton, lyrics by Gretchen Dryer and score by Arthur Rubenstein. It runs July 7-17.

JEDI-IN-THE-SKY has been reporting on Boston tryouts and sees a Broadway resurgence when Jerry Herman's new musical "La Cage Aux Folles" opens Aug. 4 at the Palace. This will be the hottest ticket since "My Fair Lady." Broadwayites will feel better.