Richmond-based Mechanics Bank amassed 2012 net income of $22.3 million, up $5.1 million from its 2011 total and the highest since 2007.
The bank has offices in Sacramento, Roseville and Yuba City.
Net income in last year's fourth quarter was $7.3 million, a 9 percent increase over the year-ago period.
The bank also declared a $25 increase in its regular quarterly dividend to $110 per share, payable on April 1 to shareholders of record on March 8.
"Our strong earnings were driven by reduced provisions to allowance for loan losses and gains in our investment portfolio," said Dianne Daiss Felton, board chairwoman.