Rich people, who are the same as everyone else except richer, were sure trying hard on Tuesday not to get swelled heads about it.

The rich people of the Peninsula were doing what ordinary people do, like going grocery shopping in BMW convertibles at stores where steak sells for $21 a pound.

“We’re down-to-earth people around here,” said Bob Mullen, a longtime resident of Woodside, which, along with Atherton and Portola Valley, was declared to be one of the 10 richest towns in the country in new figures

released Tuesday by the U.S. Census Bureau. “Wealthy people can afford to be nice and normal and down-to-earth,” Mullen said. “There are one or two people in town who are real horse’s asses, and the rest of us are nice.”

The census takers said Atherton, where the average down-to-earth person makes $112,408, is the second richest place in the United States (after Rancho Santa Fe, near San Diego) and that Woodside, where a citizen makes do with $104,667, is the sixth richest.

In Portola Valley, which is 10th richest, the average income plummets to $99,621. No other U.S. region has so many down-to-earth enclaves, although the east coast of Florida has two — Palm Beach and Indian River Shores — in the top 10.

Down at Roberts Market in Woodside, where the shelves are laden with such staples as fig confit sauce and 12 flavors of biscotti cookies, the staff said its customers were very nice and not at all stuck up, especially the ones who tip you $10 to carry their bags out to the Bentley.

“We have the best meat department in the world,” said butcher Walter Seehorn, standing behind the counter full of prime steaks and $30-a-pound shrimp. “Of course, I can’t afford to shop here myself, but that’s all right.”

“It’s a Fantasyland around here,” said Keith Nash, a fellow butcher. “Old money mixing with new money. A real country club atmosphere. I don’t think you could pull this meat counter off in Redwood City.”

On the market’s bulletin board was posted an ad for a Corvette convertible ($34,900, must sell) and the minutes of the town’s architectural review board meeting, which was considering the request of one down-to-earth guy to build a 13,653-square-foot home and paint it “greenish-taupe.”

Over at the town barber shop, longtime barber Cecelia Medina was giving a customer a haircut in exchange for three bottles of Chardonnay, not an unusual Woodside transaction. Rich people, who need haircuts in much the same way that poor people do, are hard to tell from anyone else, she said.

“You don’t ask people if they’re rich, but you can tell by looking,” she said. “Even though the wealthy computer nerds are all disheveled.”

SECLUSION RULES

A few miles southeast, in Atherton, it was hard to find a rich person in sight. That’s because most residents live on large estates behind locked gates with security keypads out front. Not a single resident was walking around during a brief visit to America’s sixth richest town.

The gates were locked. Even some of the keypads were locked.

At one house on down-to-earth Stockbridge Avenue, a woman named Ellen Moore was actually outside, because she was getting into her car and the car was outside. She said Atherton residents occasionally run into each other while walking their dogs, which also takes place outside.

Her father, retired insurance man Robert Stewart, has lived in Atherton since 1965 and doesn’t bump into his neighbors very often. He doesn’t know who they are or even where they are.

“You never see the neighbors,” he said. “They’re all of them off doing something, I suppose.”

About the only folks visible in Atherton were plumbers, electricians, contractors and landscapers. There seemed to be a laborer’s pickup parked in every other driveway, for Atherton has work to do if it has ideas of taking over the top spot in the country from Rancho Santa Fe (average income $113, 132).

The people who the laborers were laboring for, however, remained tucked away. Some of them did venture down to the fancy car wash on El Camino Real, where a quick survey of 10 vehicles emerging from the drying end revealed two Mercedes-Benzes, two BMWs and a Range Rover.

Another person hard at work on the streets of Atherton was real estate agent Ann Stoner, who was very excited about her newest listing, a down-to- earth place with four bedrooms, three baths, two Jacuzzis and a price of $3, 595,000.

“That’s a great value for the money,” she said, which is what real estate agents say about $3,595,000 houses.

The most affordable place in Atherton turned out to be the public library, even though the fine for overdue books is 20 cents a day, or twice the amount at the San Francisco Public Library.

A library card in Atherton, however, is free. Maybe that’s why most people don’t have them, a clerk said.

“The richest people don’t come to the library,” said Will White. “What they do is send their employees to a bookstore.”

That Atherton, Woodside and Portola Valley are full of rich people may be news to the U.S. government but not to Atherton, Woodside and Portola Valley.

HOME TO MOGULS

Tom Siebel, he of Siebel Systems, lives in Woodside. Charles Schwab, he of Charles Schwab, lives in Atherton. Larry Ellison, who requires no descriptive phrase after his name, lives in both Woodside and Atherton, although not at the same time.

White, the library clerk, said he has worked at the Atherton library a long time and if Ellison has ever dropped by to check out a book, he must have done so on White’s day off.