On September 3, 1996, incumbent Missoula mayor Daniel Kemmis announced his resignation, prompting the Missoula City Council to appoint Kadas to the role of mayor. He won the November 4, 1997 Missoula mayoral election and served until 2006. He was credited with handling Missoula's growth with infrastructure improvements and with mangaging the city professionally. John Engen was elected in November 2005 to succeed Kadas.
