For the 20th anniversary of Milwaukee's RiverWalk in 2009, artist John Ready created a collection called "River Gems" which were on display until 2010 at locations near the Milwaukee River.
Art - Sculpture
This piece is made of steel and bowling balls. It was on display near the Highland Avenue pedestrian bridge.
Ready is a former jeweler who is now the Gallery Director and a professor at the University of Wisconsin - La Crosse.
Links: shepherdexpress.com, www.johnreadyart.com