UniSource Energy Services is an electric and natural gas utility company serving Arizona in the United States.
It is a subsidiary of Fortis.
W. B. Foshay Co., a predecessor of Citizens Communications, acquired Southern Arizona Power of Nogales and Desert Power and Water of Kingman in 1927.
[1][2] In 2003, UniSource Energy (later UNS) acquired Citizen's Arizona gas and electric operations in 2003 and renamed them UniSource Energy Services.
[3] In 2013, Fortis announced its acquisition of UNS.