Redding, officially the City of Redding, is the county seat of Shasta County, California in the northern part of the state. It is located on the Sacramento River, which provided transportation and power in its early years. Interstate 5 passes close to the city, which has a population of 89,861.[8] Redding is the largest city in the Shasta Cascade region, and it is the fourth-largest city in the Sacramento Valley, behind SacramentoElk Grove, and Roseville.