This is not a dedicated nursing mothers room, but the Overture Center in Madison, Wisconsin has a family assist restroom on the 3rd floor off the Rotunda Lobby in Gallery III in the corridor leading into the Capital Theater. Nursing moms can choose to use this if there are no other suitable spaces to breastpump. Wisconsin protects a mothers right to openly breastfeed anywhere the public is allowed to be so moms can do that also.
Though it has a toilet, It's clean, quiet, seldom used. Has chair, electric outlets, sink, lockable door, and baby changing table. Usually open 9am to 9pm depending on performance schedule.