U.S. Customs and Border Protection (CBP) say that a truck driver arrived at the border crossing with a manifest indicating that he was hauling multiple tons of beach stones, concealing hundreds of pounds of cocaine on Sept 14, at the Tecate border crossing in California.

https://cdllife.com/2020/border-patrol-break-open-boulders-hauled-by-big-rig-make-3-9-million-bust/