The Sonoma Index was founded in 1879 by Benjamin Frank. It is the successor to the Sonoma Bulletin (1852-1855), the first California newspaper published north of San Francisco.
The Index was purchased in 1884 by Harry H. Granice, maternal grandfather of current publisher Robert M. Lynch. Granice, experienced newspaper publisher and printer from Merced County, gave the paper its present name. He owned it until his death in 1915.
He was succeeded by his eldest daughter, Celeste Granice, Murphy (Lynch's aunt) a former editor of the Index-Tribune, and her husband Walter. After 34 years at the helm, the Murphys, in 1949, sold the newspaper to Lynch and his wife, Jean. Their sons, Bill and Jim Lynch, who joined the newspaper in 1969 and 1971 respectively, will succeed their father as fourth generation co-publishers of the award-winning family newspaper.