The Gusher Days Festival is celebrating North Caddo Parish's primary industry – oil, May 4th at Earl G. Williamson Park in Oil City. The event's theme is “Where Oil and Water Mix.” The discovery and production of oil was the catalyst for forming Oil City, and it was the first site of offshore oil wells in the United States. Considered the largest natural lake of fresh water in the South covering 26,800 acres, Caddo Lake is shared by Texas and Louisiana.