A naive, unintelligent, socially inept, loud-mouth cowboy, Beauregard Decker (Don Murray), and his friend and father-figure Virgil Blessing (Arthur O'Connell) take the bus from Timber Hill, Montana to Phoenix, Arizona, to participate in a rodeo. Virgil has encouraged the 21-year-old virgin, Beau, to take an interest in "girls". Initially reluctant and frightened of the idea, Beau declares that he hopes to find an "angel" and will know her when he sees her. Beau considers women to be no different than girls and thanks that they can be tamed just as horses can be.Making trouble everywhere they go, he continues his unsophisticated behavior in Grace's Diner (The scheduled bus stop and a place for breakfast after a night of driving). Beau eats 3 raw hamburgers and drinks a quart of milk, and later calls the diner a "run down" place, offending Grace. Virgil steps in and corrects Beau saying that the diner is nice and clean and well run. In Phoenix, Beau is astonished to see so many women on the streets. At the hotel, he takes a long bath and shower, and Virgil tells him that he has a habit of overdoing everything.At the Blue Dragon Cafe, he imagines himself in love with the cafe's singer, Cherie (Marilyn Monroe), an ambitious performer from the Ozarks with aspirations of becoming a Hollywood star. Her rendition of "That Old Black Magic" entrances him and he forces her outside, despite the establishment's rules against it, kisses her and thinks that means they are engaged. Cherie is physically attracted to him but resists his plans to take her back to Montana. Beau declares his intention to marry Cherie and take the bus to Montana the following night. She has no intention of marrying him and tells him so, but he is too stubborn to listen.The next day, Beau gets a marriage license, and then takes an exhausted Cherie to the rodeo parade and the rodeo, where he rides the bucking bronco and then competes in the calf roping and the bull riding. Beau intends to marry Cherie (she realizes that Beau has no monies at all, as he paid $43 for a wedding ring) at the rodeo, but she runs away (when she sees a priest walking into the rodeo).Cherie packs her belonging and plans to take an advance from the cashier at the cafe, on account of her grandmother being sick, and run to Hollywood. Beau wins $4000 for winning every event at the rodeo.He tracks her down at the Cafe (Cherie reiterates that she has no intention of going with Beau to Montana), where she jumps out a rear window and flees. Virgil, by now, sympathizes with Cherie and allows her every opportunity to escape. Beau follows her to the bus station, where Virgil tries to delay him while she can get on a bus to LA. But Beau lassos Cherie to stop her. Beau catches her and forces her on the bus back to Montana. Cherie has to change her clothes on the bus and yearns for a man who respects her and doesn't force his will on her.On the way, they stop at Grace's Diner, the same place the bus stopped on the way to Phoenix. Cherie tries to make another getaway while Beau is asleep on the bus, but the road ahead is blocked by snow and the bus won't be leaving at all. They are all stranded there. The bus driver Carl (Robert Bray), the waitress Elma (Hope Lange), and the cafe owner Grace (Betty Field) by now all have learned that Beau is kidnapping and bullying the girl. Virgil also turns against Beau and say that he needs a good beating to drill some manners into him. Virgil and the bus driver fight him until he promises to apologize to Cherie and leave her alone. He, however, is unable to do so because he is humiliated about having been beaten.The next morning, the storm has cleared, and everybody is free to go. Beau finally apologizes to Cherie for his abusive behavior and begs her forgiveness. He wishes her well and prepares to depart without her. Cherie approaches him and confesses that she's had many boyfriends and is not the kind of woman he thinks she is. Beau confesses his lack of experience to her. Beau asks to kiss her goodbye and they share their first real kiss.All Cherie wanted from a man was respect, which she had previously told the waitress when they sat together on the bus. This new Beau attracts Cherie. He accepts her past, and this gesture touches her heart. She tells him that she will go anywhere with him. Virgil decides to stay behind. When Beau tries to coerce him to go with them, Cherie reminds him that he can't force Virgil to do what he wants. Having finally apparently learned his lesson, Beau offers Cherie his jacket and gallantly helps her onto the bus.