[2] The first branch opened in 1975 to serve the Butte, Glenn, and Tehama counties, from which the bank received its name.

At its inception in 1974, a group of farmers and small business owners within the Chico area came together to form their own bank and assist local growers.

[7] In 2013, the company opened a new $9 million campus at the Chico Airport complex, which houses information technology, operations, a call center, and training departments.

[8] The company then acquired North Valley Bank in 2014, expanding Humboldt, Trinity, and Sonoma counties.

[11] A 2021 survey published in Forbes magazine of America's Best In-State-Banks ranked Tri Counties Bank as No.

[17] In August 2021, the company entered Los Angeles County by opening a lending center in Pasadena, California.