The lady at the IGA in the Steam Boat Bend Shopping Center was explaining how the crowd seemed to be getting worse every year. Why, on Sunday it was so clogged downtown you couldn't even find a place to park for church, she said. Her girl friend Clara actually got out and started moving barricades. Then she got back in her car and called the police on her CB radio "I'll swan," the lady said. "I wish I could understand why people are so drawn to this town."

Somewhere in the geography of the American mind lay an image - a literary icon - of a small-town boy named Sam Clemens and his great muddy god the Mississippi. Even now, after we've transplanted hearts and left junk on the moon, the legends of Huck and Tom and Nigger Jim and Injun Joe won't go away. All summer long, like Canterbury pilgrims, tourists come in their Winnebagos and Airstrems and station wagons, to this rangy, ragtag, but somehow endearing river town 100 miles upstream from St. Louis. Some cannot even say why they are here.

This past weekend an estimated 20,000 people came to celebrate National Tom Sawyer Days and, yesterday, the Fourth of July, (NBC-TV helicoptered in one afternoon from Chicago for the Grand Prix of Tricycling, and a German film crew was on hand yesterday.) All of them helped turn Mark Twian's home town into a boisterous, corny, peculiarly American festival. In some ways, the natives were the most interesting of all. They seemed to be asking less of Hannibal than did the outside world. The following are taken from an observer's notes.

He is 84 and runs - seven days a week - a cigar store on Broadway. The place is narrow and cool and aromatic. Cans of Big Kick. Red Man ("America's Best Chew"). Tom Moore and Chrales Denby occupy the shelves along with Blue Shield Flints and all manner and sizes of pipes. In the back room, beneath a motionless ceiling fan and a single lamp, four men sit at a dark table playing cards, in the dingy light, they are barely visible. "Pinochle," says Clarence Schaffer. "They say Twain himself came in one day in 1902, sat down, and played a hand. I wasn't here."

Actually, Schaffer, whose khaki pants are gathered in folds at his waist, has only been here at the store 28 years. But he's been around the tobacco business nearly all his life. He used to make cigars in a shop next door, he says. "Met my wife in there 60 years ago, married her, still got her," A cackle.

Schaffer knows everybody in town. His sister is the mayor. The next evening, beneath a bunting-draped platform in Central Park, while the town oohs and ahhs about her. Lillian Hermann will take on the Chamber of Commerce president in the "World's Largest Checker Game" - played with slices of tree trunk and shuffleboard sticks. "I don't know if I'll go," says Schaffer. "I figure her to lose."

He never knew Twain, he says. The writer had left by the time he was coming up. But he did know the real-life Becky Thatcher. Her name was Laura Hawkins Frazer, and he used to go to school right behind her house. She was a grown woman by then and he was just a kid. "I'd talk to her over the fence all the time," he says. "Nicest lady you'd ever meet."

He also knew Injun Joe. Schaffer says, another character Twain took from real life. "He belonged to a tribe up the river that was wiped out completely. A (black) family name of Douglas here in town raised him. He lived to be over 100 years old. The last time I saw him he was right down the street, in the middle of the next block. He always wore the same thing: stovepipe hat, black suit, high stiff collar."

The old man squints, studying his customer (who has come in for a Pepsi). "In fact, I got a copy of Injun Joe's death certificate." He shuffles to a safe behind him that might have withstood Bonnie and Clyde. It's unlocked. He retrieves a pouch from inside and brings it back to the counter. He fingers through various treasures, including a playbill from 1906, a picture of himself projecting the town's first talkies, and a faded photo of a hawk-like figure in a white suit sitting on the steps of a house in Elmira, N.Y. This last is an original print of Mark Twain, worth a lot, he says. Finally he finds what he wants.

"Looky here," he says. "'Cause of death: Ptomaine poisoning: pickled pigs' feet. Contributory: senility.'" He ponders, as if ready to scratch his noggin. "I keep forgetting what that senility is."

A moment later, a crony drifts in. His name is Bud. He spies a picture of Schaffer. "It can't be you," he says. "Never was that good lookin."

"Bet you could get a lot for them," Bud says, pointing at the treasures with a wobbly, yellowed finger. He is emitting a low, sucking wheeze.

"If I wanted to sell 'em." Schaffer grunts.

"Yeah."

"Which I don't."

"Maybe someday you will."

After he is gone (with a new tin of Big Kick). Schaffer says: "I don't think I ever will. Sell these things. Some things you've got to hold on to. I don't think a lot of people nowasays know about that.

Daryl Stephenson, young managing editor of the daily Hannibal Courier-Post, circulation 12,000, on his town: "It works, but I think you have to like small towns. I do, though sometimes I wonder if it's not time to move on.

'Course, in a small town you've got to be more self-reliant. There's just not that much organized stuff to do."

Stephenson, a native Missourian, says Hannibal is not a bad town as small towns go. The economy is trying to hold its own, even though the shoe and cigar factories moved on long ago. There's still the Universal Atlas Cement plant south of town and just the other day they saved the rattle-trap Mark Twain Hotel on Main Street from the Eolia. Mo., is going to turn the old building, reeking with tradition, into an apartment hotel.)

And then of course there are other more esthetic attractions. Like Riverview Park, high over the city, arguably the best view in the Midwest of the Mississippi. You can go up there in the leafy cool of an evening, bring a copy of "Life on the Mississippi," gaze out on Turtle and Jackson Islands and feel like you own the world.

Last Saturday, Stephenson wrote his paper's lead editorial, entitled "Red, White, Blue Joy."

"National Tom Sawyer Days is not only one of the best Fourth of July celebrations in the country, but it is an activity that cleanses the community of pent-up animosities," he wrote. "It is the one time of the year we are brought together in a common observance of tradition and hope."

Favorite drink at the Dairy Queen on the edge of town: "The Tom and Becky." Cost: 70 cents.

The winners of the annual Tom Sawyer and Becky Thatcher contest were announced yesterday afternoon after the parade. There were six candidates for the title of Tom, and six for Becky. These had been pared down from a larger list last spring. Candidates were judged on their personality, costume and familitarity with Twain's books. The winners get to represent Hannibal nationally during the next year, with trips to Washington D.C. and other states.

The Tom title was taken by Darren Foster, 13, a seventh-grader at Hannibal Junior High, who said his grandmother helped him with his costume frayed pants, checked shirt, bandage on his big toe). Kim Zeiger, also 13, also a seventh-grader at Hannibal Junior High , won the Becky title. She carried a slate chalked with an "I Love You." She seemed to be taking it all in stride. At one point she sent her father over to the Mark Twain Dinette for a Frostop root beer.

The final beat for 3-year-olds in the Grand Prix of Tricycling on East Broadway Street, alongside the river, has just finished. The contestants have paper plates with numbers on them tied to their backs. No. 13 seemed a sure winner, but at the last minute fell off his trike and caused a terrible melee, not to say lots of tears. The winner of the heat - and eventually of the race itself - is tow-headed Shane Hipps, a taciturn racer in rolled bib overralls and a straw hat. His bike is a vision in blue, without outsized wheels. It is festooned with a special sign his daddy made.

Now the TV crew that has come from Chicago closes in for an interview. "Are you glad you won?" demands a reporters, trying to get it going.

Nod.

"Do you ride your trike a lot at home?"

Nod Finger in the mouth. Gaze around at the crowd.

"Tell me about the race, Shane."

Nothing.

A giant oil of him, given by his daughter Clara, hangs in the fine old public library on South 5th Street. The subject's hair in the portrait hasn't yet turned to gray curls. Nor is the body wreathed in cigar smoke. Nor is the subject wearing his trade-mark tropical suit. Yet there can be no mistaking who it is. It is Mark Twain. He looks at once hot-tempered, profance, sentimental, superstitious, brilliant, angular, cynical, kingly. William Dean Howells was more right than he knew when he called his friend "the Lincoln of our literature."

Ryland Capps, town barber for 40 years, sits in the Mark Twain Dinette, eating fried chicken and drinking iced tea. (You call in your order on counter phones.) Outside on the corner is the Twainland Express, a trackless yellow train that takes visitors on a tour around town. Several feet away is the author's boyhood home, now converted to a museum. All day long, people file in and out clutching cameras and kids.

In his day, says Capps, he cut everybody in town. Once he cut J.C. Penney, who was passing through. Another time John L. Lewis was in for a shave. He knew right off it was him with those bushy brows. Now Capps is retired. Last year they took out part of his lung. "This loafing is hard work," he says. "I still got my wife, and she hates me sitting around the house all day."

Is he going to any of the festivities?

"Naw." Then: "Oh, I went to the concert the other night by the Ft. Leonard Wood Army Band. That's all."

Has he read Twain? "Yeah, as a kid, but to tell you the truth. I can't remember what any of 'em were about."

What about his town? "The Holiday Inn people in Memphis told us some years ago that we weren't ready franchise. Eventually they put up 100 rooms. Now we got 250. And they said we weren't ready."

Ever think about moving away? "Don't know anywhere to go."