The most famous butter cow, the one at the Iowa State Fair, made its debut in 1911, sculpted by none other than John K. Daniels, creator of that butter version of the Minnesota state capitol. (Fun fact: Daniels lived to be 103.) The tradition has continued into the 21st century, largely thanks to Norma “Duff” Lyon, who sculpted the cow from 1957 until her retirement in 2006 (she died in 2011). When Barack Obama asked for her endorsement during his presidential primary campaign in Iowa in 2007, she gave it in the form of a 23-pound butter bust.

It is extremely tempting to imagine a butter sculptor like a dairy Michelangelo, hacking away at an enormous slab of butter to reveal the perfect hidden cow inside. (Of course, someone has already made a butter David.) But butter, even refrigerated butter, is too soft for that. Butter sculptors work like clay sculptors: they heap the sculpting material onto a wooden or wire armature, and then they mold the details. It’s less wasteful, plus if the sculpture starts to melt—with cows, ears are especially vulnerable—it’s easier to patch the whole thing back together. Simpson tells the story of an unfortunate sculptor at the 1906 Utah State Fair who spent five days carving a 40-inch tall dairymaid out of a solid block, only to hear that someone had left the door to the refrigerated compartment open and the woman’s head had begun to melt into her chest. He was able to rebuild the neck, but he needed so much butter to do it, he said, that she looked like she had a goiter.

Sarah Pratt, Lyon’s former apprentice, is the current sculptor of the Iowa butter cow (see her work of a buttered Kevin Costner at the top of this story). She works from a detailed photo, she told journalist Elaine Khosrova, who spent a week with her in her 42-degree studio for her book Butter: A Rich History. Pratt prefers Jersey cows for their expressive eyes. At the end of every fair season, Pratt usually asks her family to scrape the 600 pounds of butter off the armature and deposit it in buckets for her; doing it herself, she says, is too depressing. Sculpting butter can last for between five and 10 years. Even though she uses salted butter because it doesn’t go bad as quickly, Khosrova reports that it still smells rancid. But, hey, it’s an improvement: In earlier days, used sculpture butter was used as animal feed or, even worse, washed and repasteurized for human consumption.

The art of butter sculpture hasn’t changed much in the 150 years since Caroline Brooks carved out her first bas-reliefs. No one may remember the original Dreaming Iolanthe anymore, but contemporary butter sculptors continue to depict important historical scenes like the moon landing and pop-culture icons from Elvis and Marilyn Monroe to Jabba the Hutt and John Stamos.

Scrolling through pictures of butter sculptures on the internet (which is something Caroline Brooks could never have imagined, though she would have had a great Instagram feed) is incredibly weird, but delightfully so. There are so many other, more far-reaching ways to advertise butter now, and the margarine demon has been pretty well vanquished, but there’s still something irresistible and endearing about butter sculpture. It’s an utterly benign form of American weirdness. And it reminds you that even something as utilitarian as butter can, in the right hands, with a little imagination, become something marvelous.