National Safe Digging Month serves as a reminder to all people who plan to dig in their yard, begin a construction project or engage in any other earthmoving activity to call Wisconsinâs Diggers Hotline at 811; or in Minnesota, call Gopher State One Call at 811, at least three full business days before digging. By calling 811, residents can have underground utility lines in the work area located and identified at no cost. Itâs a simple call that can help avoid unintended consequences such as injury to you or your family, damage to your property, utility service outages or costly repairs associated with damaged lines.