I was in an ecstasy of mules. Bristling mohawks, big ears, huge nostrils. Sorrels, blacks, appaloosas, paints. They stared at me with wide-set eyes. They circled and nickered and slowly, languorously chewed grass. A mule named Charlie chomped on my notebook. A group of white mules, known for their bad attitude, kept their distance. A bony old mule named Maggie hung by a palomino colt named Ed.

It was a sunny spring afternoon at the U.S. Forest Service’s Ninemile Remount Depot, in western Montana, where working horses and mules are bred, reared, trained, and wintered. Soon, rangers from districts across the Rocky Mountains would come to retrieve their pack animals for the summer season. (The animals are crucial to resupplying outposts in federally designated wilderness areas, where motorized and wheeled vehicles are banned.) I was stopping at the depot on my way to meet Chris Eyer, who once took a packing class here. Down the hill, by the corrals, a mule-driving class was just letting out. I asked one of the students, a ranger with five summers’ experience in the nearby Bob Marshall Wilderness, whether he had ever encountered Eyer. “Yeah, I know Chris,” he said, peering at me from under the brim of a droopy-edged felt hat. “You’re the third person who’s asked me about him this week. Isn’t he, like, the most famous guy in Montana or something?”

Not quite, but Eyer does have more than thirty-two thousand followers on Instagram. He and his mules—a full string of nine—live south of the depot, on twenty acres in the Bitterroot Valley, where a wooden sign proclaims his user name: “MULE DRAGGER.” (The sign was made by his fifteen-year-old daughter.) Eyer spends most of the year working as an electrical contractor, but he volunteers as a packer for the Forest Service and various wilderness N.G.O.s in the summer. His house is full of gifts from his followers: beef jerky; small-batch whiskey; a portrait of Dulcinea, one of his mules; a leash for his dog, Otis; a never-ending supply of lotion (muleteers get chapped hands); and two bags of coffee, roasted in his honor, with the same brand that he uses on his animals—a “W” inside a heart. (He is marked with the brand, too, under his left collarbone. Last Valentine’s Day, he posted a photo with the caption “Don’t leave any more comments or direct messages about how if branding my stock isn’t that painful, then I should brand myself.”)

Eyer’s Instagram persona mixes cowboy philosophy, equine humor, advice-column maxims, and wild-horse tropes; he could sell a line of greeting cards. Many of his posts explain what he has learned from his mules: “Rufus taught me that 90% of communication is listening. It’s easier when you have big ears, but I try.” Some are saccharine: “Today they grazed in the tall grass of my heart.” Often, they pander to his female fans in the way that a country-music song might: “Love. Food. Mani. Pedi. Hair. Chloe told me it’s the way to a woman’s heart.” (Since January, seven articles of clothing have arrived in his mailbox, all size small, from seven different women. He asked me not to share the details.) Eyer attracts his more metropolitan followers with unexpected bursts of urban sass, including one recent caption in which he name-checked the Japanese fashion designer Issey Miyake. Still, he claims that his popularity isn’t about him. “It’s about an archetype of the West—I tapped into the archetype,” he told me.

Eyer grew up in Los Angeles but has deep roots in Montana; his great-grandfather was a homesteader here in the late nineteenth century, and his grandfather packed mules in the Bitterroot Valley. When I arrived at his farm, he greeted me in cowboy boots, tan leather chinks over bluejeans, a red puffy vest, and a flat-brim baseball cap. He was, he said, “doin’ pedis.” Kneeling behind a mule, he held her right hind leg on a metal stand and trimmed her hoof with a pair of nippers, scattering horseshoe-shaped chunks of gray cartilage to the ground. “Can you say hi, Pearl?” Eyer asked the mule. Pearl could not. But she had beautiful eyelashes.

This was Eyer’s sixth pedicure in two days. He planned to do the shoeing over the next few weeks, before his first trip of the season. Most packers hire farriers to do the work; Eyer, a self-proclaimed obsessive, does it all himself. He claims to feel more at home with his animals than with people. Online fame has come as something of a surprise. “A big part of me doesn’t get it or believe it’s real,” he said. “I can remember when I had twenty followers that I didn’t know and I couldn’t believe there were twenty people who gave two shits about what I did.” A year ago, Instagram featured his account on their page of suggested users. In two weeks, he gained twenty-nine thousand followers. Now people recognize him on the street. Last year, a television producer stopped him at a gas station in Augusta, Montana, and offered him a reality series. Eyer turned him down. “Frankly, it makes me a little uncomfortable,” he told me.

Before retiring to the house for a Moscow mule (vodka and ginger beer), Eyer led Pearl back to her enclosure. “All my animals had jobs before I got ’em,” he said. “They’re professionals at what they do, not pasture pets.” He believes that gainfully employed animals live longer, happier lives. Redbo, his horse, “did cows.” Chloe and Clementine, two of his mules, pulled sleighs on a Christmas-tree farm outside Chicago. He greeted the others. Olive: “Oh gosh, she has at least fifteen thousand miles on her.” Rufus: “He worked for the government before.” Ninety: “I know, I love you, too.” Cricket: “He’s the mule I’ve had the longest. He came to me, super low confidence. Scared of everything, everyone. Now he’s so confident. He’s my lead mule. There are certain animals that need a person, and I’m his person. He needed someone that would be with him day in and day out, always treat him fairly, give him a job, and just believe in him.”