Colorado Dreamin’: Don Johnson’s pretty young wife, Kelley, isn’t schussing down Aspen Mountain this season because she has a secret — make that had a secret. She’s pregnant with their second child. Kelley and Don, who live in San Francisco, already have a daughter, Grace, and are thrilly-thrill-thrilled now that they’re expecting another little Johnson. To celebrate, Don bought a pair of red walking shoes for himself at Aspen’s luxe new Prada. What, no pickles and ice cream for the little mommy? Dang, Don.

Also shopping at Prada were Mellon heiress Virginia Warner and Serena Boardman of New York’s young social swim. They checked out the fox-lined sleeping bags, a steal at $14,000, the matching pillows and the Daniel Boone hats that come with big fluffy tails. Ol’ Daniel would have wanted it that way.

Dustin Hoffman was seen carrying the designer’s shopping bags while viewing the Robert Mapplethorpe show at the Baldwin Gallery where Kevin Costner just put an important Christo drawing on hold. It’s called “Over the River” and depicts eight miles of fabric suspended over the Arkansas River, a project Christo, who’ll wrap you if you don’t get out of his way, hopes to realize in two or three years. That’s exactly when Kevin expects to be moving into the new 15,000-square-foot house he’s building with the help of his “Dances With Wolves” set designer.

It will be done in what’s called Aspen Baronial and what that’s like — well, your guess is as good as mine. Costner currently makes do in a 3,000-square-foot cabin on 80 acres overlooking Tagert Lake that he shares with his steady girlfriend, Christine Baumgartner, she of the long blond hair and retrousse nose. Kev’s tickled because his new house, being built just around the corner, will allow him to catch trout right off his front porch in the Roaring Fork River and fish his private lake right off the back porch. Sort of like “Dances With Fishies.”

Shopping in Aspen is as important as skiing, especially if you’re a star. Plus it’s patriotic. Melanie Griffith dropped into Christian Dior with her husband, Antonio Banderas, and, with his approval, picked up John Galliano’s beige Wild West fringed pants and a white shirt that buttons all the way down to Australia, ha-ha-ha. R.J. Wagner bought a new dinner jacket at Brioni that he wore on New Year’s Eve, while Jill St. John went wild in Dior’s new women’s department. R.J. didn’t move a muscle when he got the bill. Dear R.J.

Jill was also front and center when Dennis Basso showed his sables, minks and fun furs at the Little Nell Hotel. Fendi also had a stellar show at the St. Regis Hotel to benefit the Aspen Art Museum, where an Andy Warhol portrait of Aretha Franklin fetched $75,000 for the cause. Dear Andy.

Christian Slater took his new son into Baccarat where he bought the baby blue crystal bear to start the little boy’s animal collection off right. Mariah Carey and Samuel L. Jackson popped into Lana Mark’s boutique, where he bought his wife several spiffy handbags. No word on Mariah. Goldie Hawn and Kate Hudson also nipped in and nipped out with Lana’s latest, a beige alligator bag, and an ostrich skin jet tote and backpack. Goldie then wandered into Gucci to outfit her teenage son, Oliver, in everything not nailed down. She also snapped up shirts and sweaters for her beloved Kurt Russell, Oliver’s daddy. And it’s reported Michael Douglas called Frette from the set of his latest flick to have his suite, called the Silver Mountain Queen at the Brand Hotel, outfitted from top to bottom. He and Catherine Zeta-Jones are hoping to arrive sometime in the spring after both have wrapped whatever it is they’re trying to wrap.

Still, even after all that, the town’s coolest accessory remains man’s best friend. Milla Jovovich brought her little Maltese, Madness, to Aspen and tucked her into the bosom of her Prada parka everywhere she went. She also brought along her mother, Galina, and her director-boyfriend, Paul Anderson. Where she tucked him into, no one is saying. And Liz and Damon Mezzacappa were seen with their two beloved wire-haired dachshunds, Marco and Polo, at the Aspen Mountain Club atop Aspen Mountain. It being a dog’s life, Marco and Polo wag Liz and Damon.

The Aspen Mountain Club, the town’s see-and-be-seen hot spot, is its answer to the Corviglia Club in St. Moritz and the Eagle in Gstaad. In fact, they have reciprocal memberships — once you’ve handed over the $75,000 initiation fee. Simply, everyone lunches there, skiers or not, as one can always take the gondola back down the mountain right afterward. Among those standing in the buffet line at one time or another was Anne Bass looked sportively chic — chicly sportive. Anne gave a little dinner at her elegant chalet once she had tracked down enough waiters to serve it. In Aspen, that isn’t easy. They’re all out shopping.

In another part of the forest, model Rebecca Romijn-Stamos just loved her transformation to biker babe in MGM’s updated “Rollerball” re-make. She also learned to love her motorcycle, affectionately naming it “Frankenbike.” The reason — her set of wheels in the action thriller is a combination of many radically altered different parts. Get it? Some of Romijn-Stamos’s “parts” in “Rollerball” are radically altered too. Her California blonde look is disguised beneath a black wig and she flaunts a fierce facial scar. Not that she minds. “It’s fun to play somebody with a completely different look,” she says. How true. So boring to trudge through life as a beautiful, sexy blonde.

Next week, read all about C.Z. and Cornelia Guest’s holiday party.