SACRAMENTO -- A Contra Costa County man was sentenced Monday to more than 11 years in prison for running a massive marijuana operation near Auburn, authorities said.

Authorities say Adolfo Valencia Alvarez, 49, negotiated with undercover agents in November 2008 to use a property in Todd Valley outside Auburn to grow and distribute marijuana.

Agents seized approximately 10,000 marijuana plants from the site during a raid in July 2009, ending in the arrest of multiple workers, including one in possession of a .22-caliber pistol, according to authorities.

On Monday, U.S. District Judge William Shubb sentenced Alvarez to 11 years and three months in prison, according to the U.S. Attorney's Office.

David DeBolt covers breaking news. Contact him in Richmond at 510-262-2728. Follow him at Twitter.com/daviddebolt.