Federal agents from the Drug Enforcement Administration — with the help of dozens of deputies from Nevada County, as well as Butte and Yuba counties and the U.S. Forest Service — descended on eight properties on the San Juan Ridge Thursday morning in search of marijuana. Search warrants were served at properties on Kilham Circle, Silverthorne Lane and Grizzly Creek, Old Mill and Tyler-Foote Crossing roads on the Ridge, as well as Moonshine Road in Camptonville, said Nevada County Sheriff Keith Royal, Approximately 60 law enforcement officials, including members of Nevada County’s Narcotics Task Force, were on hand, eradicating more …