⚾ Play Ball! The World's Largest Collection of Detroit Tigers Autographed Baseballs is NOW OPEN! ⚾ Steve and Mary Nagengast generously donated Steve's incredible collection of 1,200 autographed Tigers baseballs to the GRPM. Hear Steve's thoughts about seeing the completed exhibit for the first time. Plan your visit to see Play Ball! and explore 3 floors of fascinating exhibits at grpm.org | Grand Rapids Public Museum