Santa Rosa is a city in and the county seat of Sonoma County, California, United States. Its estimated 2014 population was 174,170. Santa Rosa is the largest city in California's Redwood Empire, Wine Country and the North Bay; the fifth most populous city in the San Francisco Bay Area after San Jose, San Francisco, Oakland, and Fremont; and the 28th most populous city in California.History, growth and developmentBefore the arrival of Europeans, the wide valley containing Santa Rosa was home to a strong and populous tribe of Pomo natives known as the Bitakomtara. The Bitakomtara controlled the valley closely, barring passage to others until permission was arranged. Those who entered without permission were subject to harsh penalties. The tribe gathered at ceremonial times on Santa Rosa Creek near present-day Spring Lake Regional Park. Upon the arrival of Europeans, the Pomos were decimated by smallpox brought from Europe, and by the eradication efforts of Anglo settlers. By 1900 the Pomo population had decreased by 95%.