The Coast Guard recovered 43 bales of what were believed to be narcotics near Santa Catalina Island after a concerned citizen alerted the agency, a news release said.
U.S. Customs and Border Protection (CBP) confirmed the bales contained an estimated $1 million worth of marijuana.
"We appreciate the assistance provided by our partners and vigilant mariners in keeping these drugs off of our streets," said Lt. Andrew L. Fox, the Station Los Angeles-Long Beach commanding officer.
Federal officials were investigating the initial source of the bales.
Fox News' Bradford Betz contributed to this report.