Based on the information available online, the County Road 539 boat ramp in Yell County, Arkansas is a concrete boat ramp that provides access to the Petit Jean River. It is approximately 20 feet wide and can accommodate small to medium-sized boats.

According to the Arkansas Game and Fish Commission, the Petit Jean River is open to motorized and non-motorized boats, including canoes, kayaks, and small fishing boats. The commission advises boaters to be aware of potential hazards such as submerged logs and rocks, and to always wear a life jacket.

It is important to note that conditions at the County Road 539 boat ramp may change due to weather and other factors, so it is recommended to check for the latest updates before planning a boating trip.