Nothing is perfect, not even official paper maps.

I remember a hike we did on holiday in the Drôme department of France when I was a little kid, long before OSM or Google Maps or even Microsoft's Terraserver. Must have been somewhere in the mid to late 80's, I think. We did have a paper map though, and I think it was an official topographic map. We started in one valley and the plan was to hike up the ridge and then down to the neighboring valley, where we knew the Tour De France was going to pass that day. Watching the Tour was not really the main objective, otherwise we would have driven to a more suitable spot by car, but it was an incentive to keep us kids going. In hindsight we could never have made it on time.

The map clearly showed paths on both sides of the ridge, and sure enough, walking up the ridge went smoothly (if tiring) along that path. But when we arrived at the top, there was no path down the other side to be seen. There simply wasn't one, and the terrain was not exactly suitable for walking down without a path. The world simply didn't conform to the map. So we stayed there for a while and saw the Tour pass far below us, much too far to recognize anything except the helicopters but even those looked more like flies than helicopters from our high point of view.

That wasn't the only time we saw significant differences between French maps and France itself, but it was by far the most memorable one.

For people not knowing it: https://opentopomap.org

OpenStreetMap with the traditional topographic view. But I was not able to find where you wanted to hike to see the Tour de France.

I don't know exactly either, but there are some clues I thought of after I posted that story. I remember we were cheering for Flemish cyclist Fons De Wolf since he had won the stage the day before. I found out that he won stage 14 in the Tour De France of 1984 (which means my earlier estimation of mid to late 80's was not entirely correct), so the stage we observed from a distance must have been stage 15, from Domaine du Rouret in the Ardèche to Grenoble (https://en.wikipedia.org/wiki/1984_Tour_de_France#Route_and_... and https://en.wikipedia.org/wiki/1984_Tour_de_France,_Stage_12_...)

Sure enough, that passes through the Drôme departement where we were on holiday. I don't have the exact route for that stage, but it's described as a hilly stage so I assume it passed through the Vercors Massif on its way to Grenoble. That's most likely where we were that day, but where exactly I can't tell. I could ask my father but I don't think he'll remember either. It's quite a long time ago, after all.

There's an OpenTopoMap too, at least on Android. I think it's amazing how much information on the world around us we can now get with almost no effort and cost.

That's pretty good - almost as good as OS 1:25,000 maps for landforms and actually better for showing paths.

I'm often hesitant about mapping the unofficial trails, particularly the ones you aren't supposed to use. There are many around the SF bay area, some are simply non-maintained non-system trails, while others are illegal mtb paths off the allowed trail network. Some of them are so well traveled in areas with minimal erosion that they are almost as good as maintained trails, although often less well graded.

Yeah, these are basically ATV trails near my property which are probably mostly not supposed to be there. Certainly on private land although conservation land as well. I've been appreciative for them during current times and I've even been appreciative that the ATVers tend to come in and clear fallen trees and the like. But that doesn't mean I feel comfortable plotting tracks on OSM--especially those parts of the tracks on private land and especially those parts where ATVs have ripped up the terrain in said private land.

In thr Uk, I believ, paths 'legalise' themselves - once a path is established, if used continously it will become a public right of way.

Then you cant close it or obstruct it even if you are the land owner

Help contribute back to make it amazing. That's why OSM is amazing :)