Based on the latest information available, the Green River Access Site 12 Boat Ramp in Wyoming is a concrete boat ramp. It is approximately 20 feet wide and provides access to the Green River. The Green River is a popular destination for fishing and boating, and a variety of watercraft are permitted on the river, including kayaks, canoes, rafts, and motorized boats. It is important to note that regulations and restrictions may vary based on the specific section of the river being accessed, and visitors should always check with local authorities for the latest information and guidelines.