After conducting research, I was unable to find any specific information regarding the boat ramp named County Highway D Outfall in Wisconsin. There are several boat ramps located throughout the state, but without an accurate location or additional details, it is impossible to provide information on this specific ramp.

It is important to note that boat ramps in Wisconsin vary in size and type depending on the location and body of water they serve. Many of the state's popular boating destinations, such as Lake Michigan, Green Bay, and the Wisconsin River, have multiple boat ramps available for public use.

Boaters should always research and take note of any regulations or restrictions specific to the body of water they plan to use. Wisconsin has various laws and regulations in place to ensure safety on the water, including requirements for personal flotation devices, navigation lights, and registration and titling of watercraft.