Hal Holbrook likes to use exaggeration to prove a point. Back in 1954, he had earned some money acting and decided to take a fall vacation to Mount Shasta in California. The mountain is more than 14,000 feet high, and Holbrook was sure he would find some good, early season skiing on top.

It didn’t matter that he had never climbed a mountain or that he had never even thought of climbing a mountain. Up he went — 6,500 feet — in search of adventurous slopes. He spent four days alone, fainted at one point and nearly got blanketed by a landslide.

“It was insane,” says Holbrook. “I started skiing around in this glacier. The glacier swaled around into this chute which ended up where these big rocks were piled up. If I’d fallen, that would have been `Goodbye, Harry.”‘

At 71, Holbrook calls that time of youthful exaggeration his “Jack London bit” — one that he’s lucky to have survived.

That same year turned out to be a momentous one for Holbrook. In addition to his mountain-climbing experience in 1954, he began performing a show based on the works of American writer Mark Twain, best known for his adventure stories about Tom Sawyer and Huck Finn. In 42 years — that’s more than 1,800 shows — “Mark Twain Tonight!” has become one of the most famous one-man shows of this century, and has earned Holbrook an Obie Award, a Tony Award, and an Emmy nomination — to mention only a few of his acting accolades.

Holbrook will perform the show Saturday as the season opener at the Maine Center for the Arts in Orono.

“There’s something about Mark Twain’s writings that connected with something in me,” says Holbrook, speaking from his home in the Los Angeles area. “I think it has something to do with a sense of justice and his peculiar kind of satiric humor.”

And then there’s the clincher.

“I like exaggeration to prove a point,” Holbrook adds. “When exaggeration has some meaning, I think it’s delicious.”

But performing the same show on and off for more than half a lifetime seems like extreme exaggeration — otherwise known as an actor stuck in a role.

Not so, says Holbrook. He has played many other roles such as the Stage Manager in Thornton Wilder’s “Our Town” (for which he got an Emmy nomination, too) and countless other roles on TV. He has been in more than 20 films, including “The Firm,” “All the President’s Men,” “Fletch Lives,” and “Wall Street.” He has been on Broadway and off-Broadway. He has won five Emmys and been awarded an honorary doctorate from Ohio State University. He has been on stages around the country and on TV’s “Designing Women” which features his wife, actress Dixie Carter.

After all that, he has been happy to return to his signature role of depicting Mark Twain, even though Holbrook never intended the role to be such a major part of his career.

“I didn’t set out to be a solo actor,” says Holbrook, who is from South Weymouth, Mass. “I’ve done a great deal of work trying not to be one, while at the same time not letting go of this precious gold mine which I enjoy doing. There’s no question that it has its drawbacks. On the other hand, where do you find material like this, and how can you really walk away from a reputation for doing a show as well as this?”

Through the years, Holbrook has added to the script, which he adapted from Twain’s works and from books, articles and other writings on the humorist. Holbrook has also visited Twain’s various homes, including his boyhood home in Hannibal, Mo., which inspired the settings for many of Twain’s works. There, Holbrook examined photos that were useful in developing stage mannerisms and postures that Twain might have had. For Twain’s voice, Holbrook has had to rely on descriptions in news accounts of Twain’s many lectures and on recollections written in biographies on Twain.

The rest, he says, is the responsibility of the actor’s imagination.

Creating an authentic portrayal of Twain has also meant Holbrook can’t indulge himself in another form of exaggeration. No, he assures, he never thinks of himself as really being Mark Twain.

“My effort has always been to play myself,” says Holbrook.

“I’ve always felt that it would be not only foolish but cheap for me to go around pretending secretly or otherwise that I was like Mark Twain or was Mark Twain. My interest in life has been to find out who I am and try to discover that. That has taken me all my life and is still going on.”

Hal Holbrook will perform “Mark Twain Tonight!” 8 p.m. Sept. 21 at the Maine Center for the Arts in Orono. For tickets, call 581-l755.