I make trail maps that can be useful to hikers and mountaineers. Some of the areas I map have outstanding mountain scenery, but are located in areas where local regulations "frown" on independent, non-official mapmaking. To the detriment of the outdoor community, unfortunately.
My current goal is to add contour intervals to my maps. This would greatly increase their useability. So far, I have been using OpenTopoMap org as a source. OpenTopoMap solves one ...