On a scale of 1 (a stupid idea) to 10 (a great idea), where would this fall?
I looked at getting gis data from my local county. Sent an email and all I got was crickets.
It all depends on where you are at and what's available to tap into, as far as gis is concerned.
I tried to make a tree location map using phone gps meta data a couple of months ago. What a mess, the precision is too low. You can buy precision gps receivers, but they are expensive. It was a great exercise though. Now I know why trail navigation apps fail around closely spaced switchbacks in mountain areas. The gps data is too imprecise.
But maybe you know more than I
But if you can use OpenStreetMap as a baseline you may have a chance.
Originally this program was running in Python For Symbian, which is historic and funny. https://github.com/timonoko/webpy_map_server
Tiles.py seems to be how you decode the Google-tile system.