Portland, Ore.-based Umpqua Holdings Corp., parent of Umpqua Bank, has acquired the banking operations of Nevada Security Bank in Reno and its California division, Silverado Bank. Silverado Bank operates two local branches, in Roseville and Rancho Cordova. Today, those branches were operating as Umpqua banks. Umpqua said the local branches will continue to offer a full range of financial services. The acquisition was announced late Friday, after federal regulators moved to close Nevada Security Bank.