Oroville is the county seat for Butte County and about 20 or so miles from Chico. According to the 2000 U.S. Census, Oroville has a population of about 13,000, making it significantly smaller than Chico in terms of population. According to the City of Oroville, the Oroville metropolitan area has a population of 55,000 which is half as large as Chico's metro area.
As the county seat, it is home to the county's courthouse. Therefore, you will find yourself in Oroville if you need to go to family court, fight a traffic ticket, or serve on jury duty. There are, of course, other reasons to visit Oroville. They are home to Lake Oroville Recreation Area, two casinos, and more.