Video posted by the Indiana Dunes State Park shows some incredible ice formations on Lake Michigan. “Similar to building a snowman, Lake Michigan’s waves did all this work this weekend to make these boulders from ice sheets and the slushy snow we had. As the waves breaks off pieces of the ice sheets along the shore, the chunks fall off into the water. The waves then roll these ice chunks over and over again smoothing and shaping them into spheres,” the state park said in their Facebook post. The temperature and the size of the waves determine whether ice balls can grow and the results can range from ping pong ball-sized to these large boulders.”Check out the video in the player above.