Been working on a Garmin trail map of the Great Lakes area the last few years and have uploaded it to GPSFile for free. The map contains Michigan DNR Jeep Routes, US Forest roads, Drummond Island trails and a few state trails. Also state and US trails in MN. MI DNR routes are one color, US forest roads another and so are state trails. Drummond Island trails are color coded by difficulty like the paper map. Dead end trails are color coded the same except they are broken lines. Many non-dead end trails have starting points searchable under POI-Attractions-Landmarks using keyword "Trail". All starting ends start with "Trail". The map is routable and many times take you via trails seeing I made them principle highway category. Also includes many off-road parks locations.
The map is still a work in progress. Many trails are hand drawn using Google Earth and may be off by a few yards, but generally accurate.
The file is located at: