At the very start of Day 1, Mandy blew up a 747 and escaped with a parachute. She landed in the Mojave Desert, where she hid Martin Belkin's press ID. A bit later, an unknown driver picks her up, and her girlfriend, Bridgit, comes up and takes the ID.
After it had was determined that the nuclear bomb could not be disarmed, Lynne Kresge and Mike Novick concluded that the least dangerous place for the bomb to detonate was indeed the Mojave Desert. After Jack Bauer left the plane containing the bomb, he landed in the desert, while George Mason died with the bomb a few miles away.
Jack Bauer was settled in the town of Mojave after being forced to fake his death to stop being kidnapped by the Chinese. He worked in an oil drilling field under the assumed name of Frank Flynn and stayed in a room owned by Diane Huxley, beside her house. "Frank" began a romantic relationship with her, and tried to act as a father figure for Derek, Diane's son, even though he didn't trust him.