The Comprehensive Plan guides the growth of unincorporated Thurston County (areas outside of the cities). It details policies and goals for zoning and development regulations, and addresses requirements of
Washington state's Growth Management Act. It also includes specific guidelines for the subareas of Grand Mound, Rochester and Nisqually, as well as Joint Plans for the Urban Growth Areas (UGAs) of Lacey, Olympia, Rainier, Tenino, Tumwater, and Yelm.
Currently, the plan is being updated to comply with new state laws, and to account for population growth through the year 2040. Citizens may propose changes to the plan through a process called Comprehensive Plan Amendment.