[femto]

I did something like that for my local area (in about 2012). It turned into a hobby, whereby I spent a couple of years on foot exploring the local bush in minute detail and used OSM to document what I found. There are features on OSM that exist on no other map, especially off-road. I know other people do this too, as similar obscure tracks have appeared in neighbouring areas.

I've been on a number of orienteering or rogaining events where the maps look familiar, and it turns out they have used my OSM data. It's been great to see something lasting come from that mapping effort. (It's also a nice bonus in such events to be that familiar with the map and its covered area!) I suspect some local bush fire brigade members might also be looking at OSM, as a number of the fire trails I mapped seem to have had names added.