The Ohinemuri County Council first met on 17 November 1885.
[1] It was formed from a portion of Thames County.
[2] A 1919 petition[3] resulted in loss of the western part of the area[4] to a new Hauraki Plains County in 1920.
[5] The county was abolished through the 1989 local government reforms.
They are now used by Hauraki Māori Trust Board and protected by an A Category listing in Hauraki District Plan.