County

Ordinarily, the boundaries of a county are set by the state legislature. If a boundary is marked by a stream or river, the county extends to the center and remains there from the time of the county's creation, even if the stream subsequently changes course. When a lake is the boundary, the county line ordinarily extends to the bank or the low water mark. A boundary that is on the ocean extends to the three-mile limit offshore.

State law provides for the revision of the boundaries of counties. Certain state statutes proscribe the creation of a new county line too close to an already existing county seat. Ordinarily voters can petition for the expansion or division of a county where population and commercial growth justify it. Although citizens have no absolute right to prevent the alteration of county lines by state legislatures, the legislature cannot change boundaries for the purpose of diluting the voting power of some of the citizens in an election.

The state retains power to designate special districts for purposes of irrigation, flood control, fire protection, or library services, which do not affect the makeup of existing counties.