A Michigan man preparing his backyard for some renovations made a striking discovery:  158 bowling balls set in the concrete that made up his back patio, Michigan Live reports.

David Olson of Norton Shores was breaking up concrete steps that led to his back door when found the first ball.  Sparing no effort, he continued to dig around the yard, uncovering 158 balls, most of which were unpolished and without finger holes.  They were all stamped with the Brunswick brand.

Brunswick ran a bowling ball manufacturing plant in nearby Muskegon.  Looking for some background on the find, Olson contacted Kirk Bunke, site manager at the Muskegon Heritage Museum, who found the host of bowling balls right up his alley.  Bunke had heard that the factory would let workers take irregular or rejected bowling balls from the factory, and worker would use them as fill in landscaping projects.

Workers would also repurpose discarded bowling pins for table legs, and other material from other Brunswick factories in the region–which made everything from toilet seats to truck tires–were reused.  Olson’s house, built in the 1950s, is a testament to the ingenuity of residents:  he believes the original homeowner made a grid of bowling balls under the concrete patio to fill the area.

Though he’s not pinning his hopes on rolling around in wealth from his find, Olson thinks the discovery is a great bit of local history.  He plans on re-using the balls as garden edging