North Dakota Century Code, Chapter 40-38 deals with public libraries. (Prior to 1975, the Board of Education made the appointments rather than the City Commission.)
Specifically, 40-38-03 states that the Board of City Commissioners may appoint a board of five directors to govern the library. It states that members must be residents of the city and provides that one member of the governing body of the municipality or designated representative shall be a member of the board of directors of a municipal library. It states that no member of such board shall serve for more than two consecutive terms after which an interval of one year must elapse before the same member may be reappointed. NDCC 40-38-04 outlines the powers and duties of the Library Board.
On April 11, 2005, the City Commission adopted an Ordinance under its Home Rule powers, amending Section 18-0501 of the Municipal Code to expand the Library Board from five members to seven members.