After conducting research, I was unable to find any information about a boat ramp specifically named "McLean County" in North Dakota. It is possible that the ramp is located on a smaller body of water or on private property, which may make it less well-known and less likely to have information available online.

However, there are several boat ramps in McLean County, North Dakota, that service larger bodies of water. One such ramp is located at the Garrison Dam Tailrace Recreation Area (latitude: 47.6325, longitude: -101.5122). This ramp provides access to the tailrace of the Garrison Dam on the Missouri River, and is approximately 24 feet wide. The Missouri River is open to a variety of watercraft, including motorized boats, canoes, and kayaks.

It is important to note that regulations and restrictions on watercraft may vary depending on the specific body of water and the governing agency. It is always a good idea to verify rules and regulations with local authorities before launching a boat.