The City of Oroville is located in Butte County in the Sierra Nevada Foothills within the Northern Sacramento Valley. The City is considered the gateway to Lake Oroville and Feather River recreational areas. Lake Oroville, which is adjacent to the City, is the second largest lake in California. Lake Oroville was created with the construction of the Oroville Dam, the tallest earthen dam in the United States. The lake offers many sporting activities throughout the year, such as skiing, sailing, swimming, fishing, camping and picnicking. The recreation areas in the greater Oroville area are some of the most significant attractions in the Oroville region. The California Department of Parks and Recreation reported over one million visitors to Lake Oroville State Recreation Area in 2005. The number of visitors has increased significantly over the last decade. The City of Oroville has a population of approximately 18,985, and is the third largest municipality in Butte County, followed by Chico and Paradise.