Unfortunately, the boat ramp named Mississippi River - Blackhawk Upper Access near DeSoto is not in Missouri. It is actually located in Iowa along the Mississippi River. The latitude and longitude coordinates provided belong to the correct location.

According to the Iowa Department of Natural Resources, the boat ramp at Mississippi River - Blackhawk Upper Access has two lanes and is 20 feet wide. The ramp is suitable for small to medium-sized watercraft, including boats and jet skis. The ramp provides access to the Mississippi River, which is a major waterway in the United States.

It is important to note that regulations regarding watercraft on the Mississippi River can vary depending on the state and region. Boaters should always check the latest information and regulations before taking their craft on the water.