Robert 'Bob' Munro (Robin Williams), a successful California beverage company executive, is struggling with a dysfunctional family, with his materialistic wife Jamie (Cheryl Hines), his sharp-tongued teenage daughter Cassie (JoJo), and his son Carl (Josh Hutcherson), who is an adolescent Olympic weightlifting and likes Hip hop music. At a company picnic, Bob is embarrassed in front of his self-absorbed boss Todd Mallory (Will Arnett) by Cassie's militant friend Gretchen, who hurls a bottle of slimy fat all over Todd for putting unhealthy drinks in schools. Looking forward to a big family vacation in Hawaii, they are forced to cancel the trip when Todd, out of spite, tells Bob that he has to attend a meeting with the Alpine Soda company in Boulder, Colorado instead, or else he will be fired. Concealing the real reason for going there, he rents a garish Recreational vehicle from the dodgy dealer Irv (Barry Sonnenfeld) and tells his family they are traveling to the Rocky Mountains.