The County Registers of Deeds maintain county copies of the records. The microfilm is available through the Family History Library of the Church of Jesus Christ of Latter Day Saints and its international network of Family History Centers. There are 27 rolls of microfilm. Check the Family History Library Catalog at a Family History Center or online at familysearch.org for the film number of the county you need to search. The film is also available at the State Historical Society of Wisconsin Library in Madison and at the Area Research Centers of the Archives Division of the State Historical Society .
Most centers hold only the microfilm for the counties they serve.
Extractors were under instructions to record all possible variations when they could not be sure of a spelling, and if proof readers were unable to conclusively establish the correct spelling, the variations were all entered into the index. Thus, this index includes over 27,000 entries, although the number of actual births registered is somewhat less. Researchers who are unable to locate a record under the spelling they believe to have been used should check all possible variants. Registrations are supposed to be recorded in the county where the birth took place, but several instances were noted wherein a birth was registered in a county other than that of birth. The county listed in this index is the one in which the record will be located even if the birth actually occurred elsewhere.