The Warden is the main antagonist of the story and a relative of the malevolent Trout Walker, who killed Kissin' Kate Barlow and attempted to find her buried treasure. The Warden is in charge of Camp Green Lake, where she makes juvenile delinquents dig holes under the hot desert sun. The Warden runs Camp Green Lake with an iron fist and is not afraid to physically abuse and intimidate her employees. Stanley Yelnats even witnesses the Warden scratch Mr. Sir in the face after applying poisonous nail polish. The Warden maintains control of the camp through fear and intimidation and spies on the juveniles in the Wreck Room.
After X-Ray claims that he found a gold tube while digging his hole, the Warden makes the boys dig near X-Ray's hole in an attempt to find the buried treasure. When nothing turns up, the Warden becomes angry, stabs Magnet's chest with his pitchfork, and withholds water while the boys continue to dig. When Zero rebels and runs into the desert, the Warden demonstrates her cruelty by allowing him to leave and instructing Mr. Pendanski to erase his records. The Warden could care less about Zero's well-being and is willing to let him die in the desert. Zero and Stanley eventually return to the camp to unearth the buried treasure and are caught by the Warden, who engages in a twelve hour standoff with them. When Mrs. Morengo and the Attorney General arrive at Camp Green Lake, the Warden changes her tune and pretends to care about the boys. At the end of the story, the audience learns that the Warden was desperate for money and eventually sold Camp Green Lake and its land.