Resource provided by UW-Madison Robinson Map Library. [This polygon layer contains the unified school districts within the state of Wisconsin in 2017. By law, all territory in the state must be included within a public school district. The US Census Bureau identifies three types of school districts. Unified school districts serve children of all grade levels, Elementary primarily serve students in the elementary grades, and Secondary primarily serve children in grades 9-12. Out of 422 school districts in Wisconsin, 368 are considered unified districts.This layer is an aggregate of county-submitted data for school district boundaries.]