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How to Make GeoPDF Maps in Caltopo

How to Make GeoPDF Maps

A GeoPDF Map is a PDF map that you can use for GPS Navigation on a Smartphone. You can easily make your own GeoPDF maps using a FREE online mapping tool called (best used with a computer), email them to your phone, and navigate with them in a FREE GPS navigation app called Avenza Maps (IOS, Android). The US Geological Survey, the National Park Service, the National Forest Service, and the Bureau of Land Management all provide FREE GeoPDF maps for the lands and recreation trails they manage, and recommend the Avenza Smartphone app for reading them, so this is very mainstream stuff.

When I teach Smartphone GPS Navigation for Hikers, I show students how they can create their own on-trail or off-trail hiking maps in Caltopo, save them as GeoPDF documents, open them in the Avenza GPS app, and start navigating with them. It’s a straightforward process, so let me show you how it’s done. Once you understand the steps, it’s easy to create a custom map for every hike you take, print it out on paper, or open it on your smartphone to find your current location and follow your route.

You might also find the following background posts useful if you want to dig deeper into the details.

Step 1: Draw a Map in

Caltopo is a powerful online mapping tool that gives you the option to use a wide variety of maps, everything from USGS  quads to satellite imagery. Open it up, search for the area where you want to plan a hike, and draw a route, like I’ve done in the map above. This is the hike I plan to do tomorrow, climbing a mountain called North Moat, before descending on a long exposed ridge, called Red Ridge. The last time I hiked the Red Ridge Trail was about 10 years ago and I remember that the trail was difficult to follow in spots. So this time, I’ll bring a GeoPDF map on my phone, that I’ll make now.

Step 2: Print to PDF

Print to PDF

Pull down the Caltopo print menu and select “Print to PDF or JPG.” All of the PDF maps the Caltopo generates are GeoPDF maps, so there’s nothing extra that you need to do to create one.

Step 3: Select Print Area and Scale

When you select “Print”, Caltopo superimposes a transparent red overlay on the map. Drag it to the portion of the map you want to print and adjust the map scale so the red area covers everything you want to print. I’ve selected 1:24,000 below, which is a very common scale used by the US Geological Survey.

Select Print Area and Scale
Select Print Area and Scale

Step 4: Generate PDF

Navigate to the left hand side of the screen and click on the Generate PDF Button. This will generate the PDF Document linked here, which has a scale at the bottom and other important information like the current declination. If you want to start using it to navigate, attach it in an email and send it to your phone. Then “open” it in the Avenza app and you can start navigating with your phone’s GPS.

It’s really that simple and it’s entirely free.


There are a lot of things you can do, once you’ve learned a few Caltopo basics and start planning your own hiking routes. When you add GPS-enabled maps to that mix, you can mix and match on-trail navigation and off-trail navigation with ease. There’s definitely a learning curve to using, but if you’ve ever used Garmin Basecamp or a similar mapping app, you won’t have any problems coming up to speed. By making your own GeoPDF maps, you can explore areas where you’ve never been and with greater confidence, knowing that you can navigate yourself out of a jam if needed.

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  1. Thanks for the instructive post. I regularly use Caltopo for route planning and really appreciate learning how better to use all of its features.

  2. I thought that Avenza had a small limit on importing your own maps in the free version.

    • First 3 maps are FREE. Since most people only need 1 at a time, that’s not an onerous limitation Just delete the ones you don’t need and you never have to upgrade.

  3. Philip- what program are you using to view the document in step 4? I get a download generated, but it doesn’t have a .pdf file extension and I am unable to view it. Do you have to send it to Avenza to see it? Thank you-

  4. Good stuff. Just a few weeks ago I was teaching my son how to do this so he could plan a 4 day backpacking trip for his scout troop for later this summer, but now all that just went right out the door because so many of our national forest lands are closed to all recreation. Scary dry out there, even for Arizona!

  5. Louie Lindiakos

    This is only to remind myself when I am ready to learn more about it. Thanks.

  6. Philip,

    I noticed that you had planned a trek on the Cape Wrath Trail for last summer, or at least that you wrote about it. Did you end up doing that route? What kind of mapping source did you use for that? I assume CalTopo does not cover the UK? And what kind of GPS device or app? Was it adequate for that terrain and weather conditions? Did it have the grid reference #’s that the Ordnance Survey maps have? Did you use the WalkHighlands GPX files? Were those useful? As you can tell, I have a lot of questions about mapping our route for our trek next June. Would love any thoughts you have about that.

    John (and Jessica)

    • I had to postpone that trip for personal reason. Maybe next year. The bests apps for the UK are routebuddy and OS app. There is no official route. My advice would be to pick up the Harvey Maps and the couple of guidebooks about it. Buy the books for kindle so you refer to them on your walk. The walk highlands gpx files are also useful. But the spirit of Scotland walking is that you design your own route and adjust it in real time according to conditions. If you go to the OS website, there are also lots of other resources. Oh and June is probably an awful time to go due to insects.

  7. I’ve been generating caltopo pdfs for offline use on my phone for a while now but never knew they were geopdfs. Thanks for this! It looks like Avenza only displays the first page if I create a multi-page pdf. Any idea if multiple pages are supported? I often cover more ground than a single page covers in the detail I want.

    • Sorry. Don’t know off hand. My phone is full of other apps at the moment. Maybe email them and ask?

    • I have also found that only the first of a multi-page document shows up on Avenza. The way I get around this is creating multiple single page maps of my route, uploading them separately to Avenza (trying to stay below 3 maps total to avoid having to pay for an Avenza account), and then switching between them when navigating on trail. Hope that helps.

  8. I have followed the steps to download your Dolly Sod map (thanks for the great resource!) and am getting a message from Avenza saying “map not referenced”. So I can’t see where I am in relation to the map. Do you have any advice?


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