The OwlsheadGPS project features an OHV map for GPS that is compatible with many Garmin GPS units. This map contains only roads and trails (and their designations) on public lands that are open to OHV travel.
The map is designed to be scalable to increase screen drawing performance and to reduce clutter when zoomed out to a small scale. As you zoom in, more route features will appear. If you feel that you are not seeing the data you intended, try zooming in.
The map is designed optimally for color GPS units. It will function in compatible grayscale units, however the road and trail symbology will be mostly lost. You will need to “hover” the pointer over specific roads or trails to obtain their designations.