Add to the list of distinguished Oregonians the name Will Shakespeare. For it is through its summer Shakespeare festival that this town of 15,000 merits a major spot on the U.S. theatrical map.

The Oregon Shakespearean Festival Association is the site of a remarkable complex, where last year some 265,000 persons saw a dozen plays in three theaters. Its productions are given in rotating repertory, a scheme now regularly employed only by one other American theater, San Francisco's ACT, the American Conservatory Theater, meaning that within a week's stay this summer you'll be able to see at least 10 different plays. (With the opening of its "Carousel" trio of new plays, "Arena Stage also is playing on the now-rare rotating repertory scheme.)

Ashland's theatrical beginning was modest indeed: three performances of "The Merchant of Venice" before a total of 500 persons. It was the creation of Angus Bowmer, son and grandson of roaming newspapermen, who in 1935 had come to teach English at Ashland's Southern Oregon Normal school. Noting remnants of the old Chautauqua building in the heart of town, Bowmer felt that the 19th-century spot should revert to its old ways, as a center for Rogue River Valley culture.

He conned the town fathers into floating a few hundred dollars for a Fourth of July event. They took the precaution to protect their investment by booking a prize fight as the afternoon attraction. As it turned out, the profits on the repeated Shakespeare performances erased the deficit on the fight.

It's been that way ever since, onward and upward. In 1964 (shakespeare's 400th birthday year) there were five productions for 58 performances before a total attendance of nearly 61,000. By 1975, there were six productions running concurrently for 266 performances and a total attendance of 211,518. Last summer 12 plays were performed 579 times.

Now the old Chautauqua walls form part of an outdoor theater in Elizabethean design seating 1,200. There is a superbly equipped, 600-seat modern indoor theater named for Bowmer, who died two years ago. And there is an also an adaptable room, named the Black Swan, seating roughly 150, where modern, intimate plays are fittingly accommodated. The season now extends from February into October and an estimated 91 percent of the audiences live outside a 100-mile radius of Ashland.

Clearly, Ashland is doing something right.

Its main attraction is quality.There's a cadre of leading actors who appear through permission of the Actors' Equity Association. Many others have played leading roles for some years and in junior roles are graduates from the country's leading theater schools, selected tnrough Ashland's membership in the League of Regional Theaters, which ranks it in size and budget among its top four.But this remarkable organization never has achieved the national spotlight it so clearly merits because of its distance from the New York art center.

This season's "Wild Oats" is an example of Ashland's quality. John O'Keefe's tangled tale was an 18th-century companion to such classics as "The Rivals" and "The School for Scandal." But it was totally forgotten until the Royal Shakespeare Company revived it five years ago in London. I found it overrated then and very crowded on its small stage when the Folger Theatre Group had the wit to present it in Washington. Ashland's is far the best of my three "Wild Oats."

Further, it's a perilously demanding play to do, for it requires that dashing style not easily achieved by American actors in wigs and fancy dress. Because Ashland has high vocal standards, I got many of the quips that had sailed right over my head in previous exposures. Thanks to the panache developed through performing Shakespeare regularly, this is a gorgeous production, spirited and funny.

A tip-off to the quality: In the tiny orchestra pit was a real harpsichord, not the piano one might have found in many a production. Music, under the direction of Todd Barton, plays a vital role in all Ashland productions.

So do scenic design and the costuming of Jeannie Davidson. Richard L. Hay, resident designer since 1969, achieves stunning effects on the Bowmer's thrust stage, its appearance and shape changing for each of the productions. One of his challenges is to make the same designs suit the outdoor stage, where generally the plays are given without intermission. Germany is the only country where Shakespeare is regularly performed without intermission and the effect on the plays' narrative drive is enriching. You don't have time to think of those plot holes in such works as "Romeo and Juliet" and "Othello."

"Twelfth Night" is having its seventh Ashland production this year and over the summers Ashland has run through the entire Shakespeare canon of 37 plays three times. Hay seems to be the only designer in the world to have created sets for all 37 works.

Some of the locals are inclined to be testy about the expansion beyond Shakespeare, a practice new followed by all the major Shakespeare festivals. This spring, American theater is represented by Arthur Miller's "Death of a Salesman" and Canada's by "Artichoke," a new play by Joanna M. Glass, whose "To Grandmother's House We Go" played recently on Broadway.

Artistic Director Jerry Turner observes that to confine productions to Shakespeare would "risk living in a vacumm," so there are such modern works as Athol Fugard's "Sizwe Banzi Is Dead" and "The Island" (to be done this summer), Pinter's "The Birthday Party," Albee's "Seascape" and James McLure's "Lone Star."

Executive Director William W. Patton keeps his eyes on both the budget and the future. With annual expenses now reaching $3 million, Patton proudly notes that Ashland takes in over 70 percent of its expenses at the box office, a far higher average than most nonprofit theaters. But he says that "rising costs are a clear worry. Ahead, as with Arena Stage and other LORT theaters, deficits will loom larger."

So, already at work is "The Next Fifty Years" committee, aiming for a $10-million endowment fund by 1985, the group's 59th anniversary. As that year approaches, Ashland can look for visits by now-celebrated alums such as Dick Cavett, William Hurt, Powers Booth, George Peppard, Eric Miller, Le Clanche du Rand, Rick Hamilton (of "Amadeus"), Jean Smart (of "Piaf"), TV's David O'Brien and Fredi Olster.

If you're planning your summer holiday, think of Oregon's Will and the Great Northwest. "Do come," says Ginger Rogers, who has a house near here, "Come, but don't stay! The joy of Oregon is that so far we don't have too many people out here."