Sal and Montana Slim begin bar hopping and partying with the other revelers at the Cheyenne Wild West Festival. Sal gets drunk and chases various women, spending all but two dollars of the seven he has left. After almost taking a bus to a middle-of-nowhere town in Colorado with a girl he picks up, Sal eventually starts to feel bad about the situation he has put himself in: almost broke, drunk, and tired. He finds a spot on a bench in the bus station and sleeps till the morning. When he wakes, Montana Slim is gone. Sal is ready to leave Cheyenne and the Wild West Festival.
He picks up a few rides outside Cheyenne and again begins to feel the excitement of getting to Denver. After a brief nap at a filling station, he finally catches his ride into Denver and arrives in the city at Larimer Street.
In Denver, Sal finds his friend Chad King, and Chad picks him up from the bus station. He finds out that Chad in no longer friends with Dean or Carlo Marx, both of whom are in Denver, and begins to feel pulled between the two groups (Dean's friends and Chad's friends). He goes back to Chad's house to take a nap and eat some food, but he is worried about finding Dean and Carlo.
In chapter six the reader begins to learn some of the history of Dean Moriarty. Dean was from Denver originally and had been raised on Larimer Street. His father had been an alcoholic, and at the age of six Dean had pleaded before a judge to set his father free from jail. He had begged for money on the streets of Denver and eventually started hanging around pool halls. After he "set a Denver record for stealing cars" he was sent to reform school.
Sal moves into an apartment owned by the parents of another Denver friend, Tim Gray, and begins to take part in the life of the city, visiting its bars, drinking, and meeting old and new friends. Eventually, Carlo finds out that Sal is in the city and tracks him down. Carlo and Dean are making big plans for their lives. Dean is getting a divorce from Marylou but still sleeping with her in the interim, all the while carrying on an affair with another woman. Both are doing a lot of drugs, Benzedrine, and staying up all night to talk.
When Sal arrives at Dean's apartment, Dean answers the door naked and excitedly decides he must take Sal out on the town to find a woman. They go to Denver's Mexican-town, where they find the house of some waitress sisters and begin a wild party. Eventually, they decide to take the party to Sal's apartment, but Sal's roommate, Roland Major, refuses to let them in. They decide to head back to the downtown night spots instead, where Sal eventually finds himself alone and finally broke, having spent his last dollar.
The Denver group begins planning a trip to the mountains. Eddie, Sal's friend from the road, calls looking for work. Dean takes Sal and Eddie to the markets, and they get offered a job working from four in the morning till six in the evening. The next morning, Eddie shows up for the job but Sal does not. Instead, Sal spends his days and nights visiting various parties all over Denver, listening to Carlo Marx's poetry in late-night reading sessions, and observing Dean. Carlo and Dean, the "amazing maniacs," spend hours and hours talking, staying up all night discussing random and varied topics and making plans to go to San Francisco.
Sal then takes off for a trip to the mountains with Babe, Ray Rawlins, and Tim Gray. At an old mining town turned tourist attraction, they fix up an old shack for parties, go to the opera, and drink. The group throws a big party at their shack. It eventually gets crashed by fraternity boys, so instead they hit the town bars, where Ray Rawlins gets in a fight. Outside, standing on a mountain's edge, they yells and howl into the night, in awe of the vastness of the landscape. As the group leaves the mining town, Sal begins to feel the urge to go with Carlo and Dean to San Francisco.
Back in Denver, Sal finds out that Dean and Carlo had been in the mountains the whole time he had been there. Dean gets Sal together with Rita Bettencourt, the girl that Dean had originally wanted to get Sal together with when they first met up in Denver. Rita and Sal have awkward sex and talk about what they want from their lives. Sal takes one last lamentable walk through the streets of Denver, picks up the money his aunt wired to him, finds the shirt that his friend Eddie had left with earlier in the journey, and buys a bus ticket to San Francisco. In a last-minute phone call, Dean says that he and Carlo might join him there. Sal realizes that the whole time he had been in Denver, he had not talked with Dean for more than five minutes.
Chapters five, six, and seven introduce the reader more fully to the beatnik lifestyle that Sal and his friends try to live. Beginning with the Wild West Festival and continuing into Denver, the reader gets a sense of the kind of free-wheeling lifestyle that continues through the rest of the book: heavy drinking, drugs, multiple sexual partners, and other excesses are all available and are encouraged within the group. There is little thought of tomorrow. Dean offers to find Sal a job and comments that everybody is broke, but there is little worry about money. These first days in Denver set the tone for the kind of hedonist lifestyle Dean, Sal, Carlo, and the rest of the group seek out in the hope of truly living life to its fullest. They are days that are "filled with eminent peril," as Sal says, quoting W.C. Fields. Yet the peril is invited and enjoyed, not something to be afraid of.
Chapter seven also attempts briefly to show the reader the cultural lines that classify these beatniks. Sal's roommate, Roland Major, writes Hemingwayan stories about young Denver residents who become annoyed and despondent over the "arty types" of Denver. According to Sal, the point of the story is that "The arty types were all over America, sucking up its blood." The Beats, while concerned with intellectualism and writing, were not these "arty types." Instead, they sought to find and be a more real America, an America hiding behind the facade of popular culture and pretentious critics.
Chapters eight, nine, and ten deepen the frenetic and, often, insane lifestyle of Sal and his Denver friends. Sal continues to deal with his deepening involvement with this group on the fringes of society. He begins to even vaguely define what being a part of the Beats truly means. During his trip to the mountains he realizes that even among his Denver friends he is slowly becoming more like Dean and Carlo, being drawn into their dark and frenetic world. Sal describes Dean and Carlo as people of "gloom, rising from the underground, the sordid hipsters of America."
These chapters also continue to draw dividing lines between that "sordid" world of Sal, Dean, and Carlo and that of mainstream America. Central City, the mining town they visit in the mountains, becomes another emblem of how America is slowly turning into a tourist destination. Though Sal has the freedom to go wherever he wants, he finds fewer and fewer places worthy of exploration. While Sal and his Denver friends try to bring their life and insanity to this mountain town, ultimately, they find they do not have a place there, so they leave sad and hung over.
Sal also feels distress over the sad state of affairs between people-they are no longer able to communicate with each other because of the societal pressures being forced upon young people. In one passage, after having a poor sexual experience with Rita Bettencourt, Sal sadly notes that "Boys and girls in America have such a sad time together; sophistication demands that they submit to sex immediately without ... real straight talk about souls, for life is holy and ... precious." It is in these brief moments of reflection between the constant coming and going of Sal and the rest of the beatniks that the reader gets a sense of the cultural influence and post-war sensibility beginning to take shape in America in the late 1940s and early 1950s. These brief reflections give rise to the outright rebellion that the Beat generation embodied during this time.