Wis. Stat. § 59.75: Certificates and records as evidence.

The certificate and also the official record of the county surveyor when produced by the legal custodian thereof, or any of the county surveyor’s deputies, when duly signed by the county surveyor in his or her official capacity, shall be admitted as evidence in any court within the state, but the same may be explained or rebutted by other evidence. If any county surveyor or any of his or her deputies are interested in any tract of land a survey of which becomes necessary, such survey may be executed by any professional land surveyor appointed by the board.