The town was finally incorporated in 1906. The government of the city was organized by the creation of a board of trustees and the election of city officials. With incorporation accomplished and the city government organized, Oroville entered upon a period of rapid municipal improvement. In the next 12 years, many miles of concrete sidewalks were constructed and the business section of the city and of Bird Street were paved, a levee was built as well as a grammer school, sanitary and storm water sewer systems were put in, 2 churches, an exposition building and a Carnegie Library were constructed.

Bidwell Bar, one of the first gold mining sites in California, is now under the water of enormous Lake Oroville. Bidwell Bar is memorialized by the Bidwell Bar Bridge, an original remnant from the area and the first suspension bridge in California (California Historical Landmark #314).