District 1 supervisor Denny Barney plans to step down next month.
Barney has represented District 1, which covers the East Valley, since he was first elected in 2012.
He was re-elected in 2016.
Barney took over as CEO and president of the East Valley Partnership in May of last year. It is a nonpartisan coalition that advocated for economic development and other issues for the East Valley.
He said he is resigning from the board to focus on the Partnership. The supervisors oversee the operation of Maricopa County government.
Maricopa is the fourth largest county in the United States with more than 4.3 million people.
Barney will step down on Feb. 1. The remaining board members will appoint his replacement. Details on that process are expected next week.
