https://caltopo.com is a free online mapping tool that features many map overlays and tracks to assist you in planning a trip.
You should sign up for an account. When you are signed in you can save your route and it will automatically save as you make changes.
Using the different layers
There are a ton of layers to choose from. I primarily use these three:
- Topographic Maps – USGS 7.5′ – This is your standard topographic map, all compiled together into one big continuous thing covering the whole US. I always use this layer for making PDFs and printing.
- Topographic Maps – MapBuilder Topo – Zooming out while using USGS 7.5′ quickly becomes an illegible mess. MapBuilder Topo scales, meaning that it will display less detailed information as you zoom out which makes it easier to get a broader view of the land and your route. It also features a lot of the most popular trails as red lines, which can be handy for linking trails together.
- Google Layers – Satellite – You can get a good general sense of the terrain by seeing the satellite image. You can get a good sense of what you’ll be dealing with by seeing if there will be dense forest, scattered shrubs, sand, granite, talus, etc.
You can import a GPS track with waypoints using the import tool at the top of the screen.
For adding my own stuff, I use markers and lines. When zoomed in enough, your lines can snap to routes that are already in the system.