Using GaiaGPS iPhone App for the CDT

Here are some step-by-step instructions for getting GaiaGPS working for the CDT.  I felt like I generally had the most fun setup for GPS out of anyone I met on the trail in 2011.  The main advantage comes if you’re already going to carry an iPhone for other reasons – you save weight by making this your GPS.  I also really enjoyed the UI of GaiaGPS on the iPhone, it was always an intuitive pleasure to use.  I was the envy of at least one other CDT hiker 🙂  The key feature of using GaiaGPS over a lot of other GPS solutions is that you’re going to end up with exactly the same USGS maps that you’ll be printing from Ley.  This makes figuring out where you are on the map a ton easier.

Read on after the jump for all the gory details.

For best results, have a waterproof case, otherwise you won’t be navigating in the rain.  I also would recommend at least an iPhone 4.  The 3GS chokes on the big tracks we’re going to load.

  1. Buy GaiaGPS from iTunes and install it.  It’s currently $10, I think I paid $20.
  2. Download the CDT tracks you want to use to a computer.  Starman has recently posted (2012/02/14better tracks that you should probably use!  I used the Sly (that’s a trailname) track that, as I understand, someone hand-created from Ley’s maps.  You want to get the ones that are in the direction you’re going (NB or SB), and you want the ones that are per-state.  The caveats with the Sly tracks are that they start/finish at Antelope Wells and they’re not perfect.  I believe they were created in 2009, so they are already out of date in some areas.  I rarely found that I needed the track itself to find myself though, usually I could find where I was on the paper map and then I was off.
  3. So, now you should have a collection of 4 gpx files, one per state.  You need to email them to, one per email, with an appropriate subject (i.e. “CDT CO” for the Colorado gpx).  The body of the email can be empty.
  4. Go into your iPhone, and open the 4 reply emails from  Each will have a link in it that you need to click.  After you click the link, it will open GaiaGPS and then freeze for awhile, and eventually tell you that it has successfully imported the track.
  5. Turn on your WiFi.  Time to download maps onto your iPhone:  this is the step that will take you a long time.  It took me days!  From my tests lately, it seems that the topo map server is doing better, so hopefully it’s smoother for you.  So, why do we have to do this step?  On most GPS devices, you buy the device and then either purchase or are given the topo maps as a download or via a DVD.  When you buy GaiaGPS, they give you access to their topo map server, but it’s up to you to tell them which maps you want.  What we’re going to do is load each state’s track, and then tell GaiaGPS to download a swath of topo maps around the track.  Open GaiaGPS, then go to “Saved”.  Click the tracks button at the top left corner and then select your first track (i.e. “CDT CO”).  This will bring up a summary page for the track.  Touch anywhere in the little preview area (the map) then click on “Download Maps for Track”.  Repeat for each of your 4 tracks.

There are some other things you can do to make your iPhone + GaiaGPS combo most effective.  The main problem you’re going to run into is that having GaiaGPS open drains your battery alarmingly quickly.   Thus, your best bet is generally to figure out where you are, then get your phone turned off again.  Using this method, I figured I could use the GPS twice a day for a week without needing any backup battery (that’s on top of using my iPhone to journal every night and listen to music occasionally.  YMMV).  The bright side is that iPhones are pretty snappy at figuring out where you are using just the GPS chip (they’re even faster if you have cell service or wifi, but you generally won’t on the trail!).

It doesn’t help that whenever your iPhone is on, it’s going to be searching for a cell signal.  If you have an iPhone newer than a 3GS, all you’re really going to be able to do is make sure that you leave your phone in Airplane mode until you need to navigate (or just leave the iPhone off).  If you have an iPhone 3GS, and you’re technically savvy, I suggest you jailbreak your phone.  You can then install SBSettings and the Phone toggle.  That way you can have the GPS on but leave the cell tower searching off.  I haven’t discovered if this is possible for iPhones newer than a 3GS (so far it seems the answer is “not possible”).  On that note, if you do end up using a 3GS or lower, you’re going to have to break up the per-state tracks into smaller chunks.  GPSBabel can help you here.

GaiaGPS also supports OpenStreetMap as a map source, so I downloaded most of the 4 states in that too.  I didn’t want to carry the DeLorme atlas pages that are recommended by Yogi and Ley, so this was my solution.  I never used them, but it still seems like a good idea.

I recommend you check over the track when you are in trail towns, looking at the next section on the phone vs what your Ley maps show.  The route changes significantly in places and you could easily end up off the edge of your downloaded maps.  You’ll still be able to navigate coarsely back towards the CDT, but it isn’t as fun.  Also, any purple routes you want to take, you’ll want to manually download the maps for those areas (you can do this by scrolling around the map when you have internet connectivity, and using the “download” button right in the map area to select rectangles of map to download).

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8 Responses to Using GaiaGPS iPhone App for the CDT

  1. Hey, I will have to play with this….I just got a 4gs. (With the LifeProof waterproof case) By the way the link you have to the WhiteBlaze link of track files is NOT the OOO files, they are the OLD J. Ley files posted by Sly. They are based on an OLD Google earth file. I have a site set up to post the actual OOO files if you want to link there instead. The Bear Creek files match exactly on to the OOO track files. But, as of now they are only waypoint files. Hopefully Montana will be posted soon.


    • High Life says:

      Test that case frank ( without the phone in it )
      bought mine yesterday , tested it and it leaks
      returning for another one …

  2. Darren says:

    HI Ryley,

    Get information on this app. I am going to test this out before my CDT hike this year. I am having troubles with step 5 – downloading the maps. I follow your instructions and the app doesn’t seem to to be doing anything. Will I suddenly get a message two days from now that says the maps are downloaded or am I doing something wrong?

    More info please!



  3. Ryley says:

    Darren – go to the Map icon (bottom left) in GaiaGPS, and click on the little “layers” button (it’s the 3rd blue button down in the top right corner). Do you have USGS Topo selected there, or if not, what is selected?

    If you don’t have USGS Topo, and instead it’s something like “myTopo”, you need to do what this link says:

    All that being said, what should happen when you select your track, then touch the map, then touch “Download Maps for Track” is that it should switch to the Map screen (eventually) and show a progress bar as it downloads the topo maps.

  4. Andrew says:

    Hi there. I am one of the developers of Gaia GPS. If anyone here has any questions about the app, please send me email at and I’ll be happy to assist.

  5. Don't Panic says:

    Sweet stuff — any idea how much space all those maps take up on the phone? (it’s got to be several gigs, right?)

  6. Ryley says:

    Yeah, they take up a bit – the way I did it last year, it was about 1 gig, but using the newer method “download maps for track” that they added to GaiaGPS, I have a feeling it might be a bit bigger… still less than 2 gigs I would guess.

  7. Douglas Greer says:

    Hi ryley. This is your uncle Doug
    I am just trying to follow you on your travels, but I am not very computer literate. I will keep trying.. One day you may even send me a message
    Doug Greer

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