Inspired by what I see here down under (where all MTB trails have been mapped out by the community) and also by Strava, who seem inclined to
move from google maps to OSM, I decided to add some of my gpx tracks to openstreetmap.org, starting with Anderson Park:
http://www.openstreetmap.org/?lat=42.6933&lon=-84.61963&zoom=16&layers=M. The track currently only renders in a few zoom levels and is not yet visible on the cycle map (opencyclemap.org, or simply as a clickable layer in openstreetmap.org), but I believe that it will be added in a few days.
I am not sure if OSM will be
the way forward, but the fact that MTB trails can be added is obviously a benefit for us. I saw that the Poto is already available; CRAMBA appears active in putting tracks up too. The maps look quite a bit different than the google maps that we are all used to, but the learning curve for using the maps isn't steep (neither is it for generating the maps by the way). In addition to browsing the maps on the computer, smartphone apps using these data are available. I used it here down under to navigate the trails and I suspect it will be equally useful in Michigan.
[edit: link for a relation of features for route>mtb>Anderson Park:
http://www.openstreetmap.org/?relation=2263189 - I only added the main loops to the relation, and left the connectors, shortcuts, and parking out.]