CUSTER, S.D. (MITCHELLNOW) It’s that time of year for baby bison at Custer State Park. Park officials announced the first bison calf has been spotted to kick off the spring season. A picture was captured of the mother bison and her new baby. More calves are expected to pop up in the coming weeks around the area. Park officials are still reminding folks to keep their distance when enjoying the sights of the bison.