Digital mapping

Sign in to Caltopo

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Locate a feature, add a line, and create a track

Adding a line to your map will let you create a track you can share with others or download as a GPX file to load on to your GPS device or smartphone GPS app, such as Gaia GPS

  1. Type in the name of a feature or location into the search box in the top center to the right of the binoculars. For example, enter: Mount Whitney, CA
  2. Scroll the map around to find where you want to start. E.g., the Mount Whitney Main Trail trailhead.
  3. Add a line: Click on the green "+ Add" near the top left and select "Line" or, equivalently, select "+ Add New Object" in green on the left and select "Line".
  4. Name your lin/track: Name your track by filling in the "Label" of the popup in the lower right of the screen, and add any comments, change the line style, etc., by filling in or playing with the different options. Note: you can always do this later by finding the track in the "Lines & Polygons" menu on the left side of the screen and clicking on the pencil graphic to the right of the track.
  5. Draw the track: Move the cursor to the point you wish to start your track, and single left click to begin drawing your line. Continue to single left click in various places to draw the path of your track. If you make a mistake, use the "Esc"/"Escape" key to undo your last left click. Double left click to stop drawing your track.
  6. "Snap to" trail: If you are zoomed in enough (scrolling the mouse wheel or clicking the "+" in the upper left of the map), once you begin to add a line, certain trails will be highlighted in yellow, which means you can mouse over the yellow line to have Caltopo automatically follow the yellow highlighting for you. To do this you may need to mouse over the yellow highlighting and left click once when the trail turns from yellow to red. Once you've clicked within the highlighted section, the track will begin snapping to the trails.

View your line/track elevation profile

After creating a track, simply click on it and from the menu select "Profile" for a simple elevation profile, or "Terrain Statistics" for one with more information, including information on slope, tree cover, elevation, etc.

Save your map once you've made a change

Once you've made a change to the map, you can, and should, save it. From then on the map will automatically save as you make edits to it. To save your map initially, click "Save this map" in red near the upper left of the window.

Add some markers to clarify points of interest

Add markers to your map to clarify points of interest, such as a campsite, parking area, peak, pass, etc.

  1. Add a marker: Click on the green "+ Add" near the top left and select "Marker".
  2. Fill in the details: Name the marker by giving it a "Label", explain what's going on there by filling in the "Comments", and optionally specify GPS coordinates if you know them.
  3. Finally, change the style or color by clicking on the relevant icons (either the red circle to the right of "Style" or the red square to the right of "Color". Then select either the icon (say a campfire) or color you desire.

Change the map options to add change the base map, add slope angle shading, etc.

Change the default base layer

Change the base map in the upper right hand corner of the screen, under "Base Layers", by clicking on the default "MapBuilder Topo" listing and selecting something else. From there one can select various maps for various purposes. For example:

  1. snow cover is visible using the Sentinel Weekly layer under "Live Satellites". Tips: False Color Green is easier to view than the default, and sometimes clouds will mess up the most recent satellite reading, so use the drop-down to select an earlier date;
  2. the "Scanned Topos" (USGS 7.5' maps) shows more trails than the MapBuilder Topo (some of which may no longer be maintained, such as the 'trail' over Harrison Pass);
  3. the "Historic Maps" map has even more old trails (which are even less likely to exist); and
  4. the "Satellite" map under "Google Layers" unsurprisingly shows a satellite view, which can help show where tree cover is, how many parking spots a trailhead has, or help locate routes, such as the "blowhole" on Eckert's Jonah's Joy route on Whaleback.

Add more base layers

Instead of changing the default layer, it's possible to superimpose layers upon one another by clicking "+ Stack Base Layer" in the Base Layers section, and then adjusting the opacity of that lawyer with a slider. For example, making the default layer the Scanned Topos/USGS 7.5' series maps, and then adding the Sentinel Weekly layer (and then adjusting the Sentinel Weekly layer's opacity) will show both the USGS map and snow cover.

Add other options, such as slope angle shading, land ownership, and weather data

  1. Add slope angle shading to help determine how steep a cross country pass might be: Click on "Slope Angle Shading" in the "Map Overlays" section.
  2. Add a Weather grid showing 24 hour highs and lows, weather shading, and a wind plot by selecting the appropriate options under "Forecasts".

Export your GPX to download it

Export your map to a GPX file so you can download it and load it into your GPS receiver or into your smartphone based GPS software.

  1. Click on "Export" near the top of the window, and select "Download GPX File".

Add elevation data to your GPX file

For reasons unknown, Caltopo does not include elevation data in download GPX files, even though the spec allows for it. Elevation data can be added to the tracks within your GPX file by using the GPS Visualizer elevation tool. Simply visit the sit, select "Choose File" under "Upload a file" and then click "Convert & add data". GPS Visualizer will then use a Digital Elevation Model to add elevation data to the GPX file.

The upshot of adding this is that it will help you more quickly figure out, on day 6 of a backpack, how much elevation gain day 7 will have, assuming your tracks are divided up into days. Assuming of course your GPS software or device allows for this, as GaiaGPS does.

Load the GPX file into your smartphone based GPS software

  1. Email the GPX file to yourself by attaching to an email addressed to.. yourself.
  2. Check your email from your phone, and likely tap and hold on the GPX file attachment, and select to "Open with", "Send to", etc. Gaia GPS.
  3. Note: be sure to pre-download your maps on whatever smartphone app you are using, because otherwise you're liable to walk off the end of your map if it's not completely downloaded.