The 22nd annual Missouri Mines Rock Swap returns to Park Hills this weekend. Art Hebrank with the Missouri Mines State Historic Site says anywhere from 2,500 to 3,000 people show up each year to rock out.

The event is free and also includes access to the historic site’s mining-mineral museum. Hebrank says the rock collectors they welcome are from all over and have quite the wares, like a group last year who came from Florida.

The Rock Swap begins at 9 each morning on Friday, Saturday and Sunday at the Missouri Mines Historic Site, located on Highway 32 in Park ills at the Flat River Drive overpass just west of U.S. Highway 67.