Gaia GPS has a feature to download maps for any track or route.
1. Choose the Track from your Saved Track List
2. Choose "Download Map Along Track"
3. The map download follows these rules:
- Map Source - The downloaded map uses the map source currently selected
- Map Resolution/Zoom Level - The download includes zoom level 9-16. This will give you the max resolution for USGS topos, and very high resolution maps for sources like World Topo. This tends to be about right for most sources.
- Width of Download - The downloaded map includes 5 "tiles" on each side of the line.