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How to use the iPhone as a GPS mapping device for backpacking

close-up of an iPhone 4 in a simple case with a mapping application running

The iPhone is a viable tool to use as a GPS and mapping device for backpacking trips worldwide. In many ways it is superior to traditional mapping GPS units like the Garmin Oregon. This post will tell you how to get the most of your iPhone as a backpacking GPS.

The method for using the iPhone for backpacking is to use apps that let you preload the appropriate maps and data files over WiFi. When you are out on the trail without WIFI or cell service, you can use the preloaded maps along with the iPhone’s GPS.

If you already own an iPhone, then the cost of using it as a GPS/Mapping device for backpacking is very reasonable.

iOS Hardware Models

For purposes of this article (GPS and mapping), the iOS devices vary in only two ways: GPS Chip and Battery Drain.

First, some iOS devices have a GPS chip and some do not.

Second, there are subtle but very important differences in battery drain between the different models and different cellular providers. See the Battery Drain and Different Models of iPhones section below for critical information.

To clarify a common misconception: You do NOT need WIFI or Cellular connection for the GPS chip to work; however you do need to have pre-downloaded the map content in order to have your current location show up on a map.


Gaia GPS displaying OpenCycleMap of a section of the Lycian Way in Turkey. Red lines and blue pins show our intended route (2 alternatives shown). The brown dashed lines show trails that have been added by users to the OpenStreetMap database, wiki-style. OpenCycleMap and Satellite imagery are especially important when hiking in Turkey because the government does not publish any topographic maps. Using an iPhone with a $10 app (in this case Gaia GPS) we carried maps, satellite imagery, and track data for ~600 miles of trails in Turkey!

How to Choose your Mapping Apps

There are hundreds of iPhone mapping/GPS applications to choose from, and there are seemingly new ones everyday. You should probably buy a couple applications; they are not expensive, and the map content is usually free (unlike Garmin, where you pay substantially for map content).

Many of the mapping apps are not designed for hikers, and many of those that are designed for hikers are seriously flawed. Here is an annotated list of the (~80) apps we reviewed, including more detailed information about each app, and a list of great apps that are not mentioned below. We are maintaining the list and appreciate leads on apps we misssed and corrections to inaccurate data; please post comments and suggestions below.

Before choosing an app, you need to decide which types of maps you want to view while hiking. You may want to use more than one app if you care about more than one map type. After deciding which map type you want you can then evaluate the features and usability of the apps that provide that map type. Here are the general classes of maps:

  1. National Mapping Agency maps - Topographic maps issued by the government that provide coverage for an entire country (USGS, NRCan, OS, IGN, LINZ, etc). These maps are almost always the most accurate and detailed source of topographic and geographic information, although they often do not have the most current cultural changes, such as new trails. Some governments license their map data to the apps at no charge (USA, Canada, New Zealand, and some UK maps), and others do not (UK's best maps, France, Australia). When you use an app that gives access to freely licensed maps (for example USGS) you usually do not need to pay any fees (beyond the initial cost of the app) to download an unlimited amount of map data. When you use an app that gives access to maps for which the app developer must pay licensing fees, then you will need to pay for the map content. Prices vary wildly, depending on the fees that must be paid to the government for use of the maps. For example: iPhiGeNie charges 14 Euros per year to access the all maps that IGN publishes (not so bad); ViewRanger charges 90 GBP for the 1:50K LandRanger series, the Explorer series is additional (wow!).
    1. For access to USGS and NRCan (USA and Canada) maps we like Topo Maps and Gaia GPS. We use both of these apps and believe they are better than the numerous other apps we have evaluated.

      Topo Maps is easier to learn and use but provides only USGS and NRCan maps and has very limited functionality. For a user who only cares about viewing USGS/NRCan quads and uses only waypoints (not tracks or routes), this is a fantastic simple app.

      Gaia GPS provides Satellite imagery and OpenCycleMaps in addition to USGS, and has a richer set of features, but takes longer to learn to use. For a user who wants the most complete set of functionality and the best selection of map sources, this is the best available app for the US and Canada.

    2. For access to LINZ (New Zealand) maps we like Gaia GPS. Same comments as above: You get complete functionality and, in addition to LINZ maps, you get OpenCycleMaps and Satellite imagery.
    3. For access to IGN (France), IGN (Spain), and ICC (Catalan) maps we like iPhiGeNie (based on evaluation at our desks, we have not tried it in the field).

    4. For access to OS maps (UK) we suggest two alternatives.

      UK Map offers freely licensed OS maps, which are not as detailed as the Explorer and LandRanger series, but will suffice for many users (especially price-sensitive users). It is elegant and easy to use, but does not support waypoints or tracks.

      ViewRanger is a solid full-featured app that offers the gold standard Explorer and LandRanger OS maps. It is too bad that the Ordnance Survey charges such high licensing fees, but serious back-country walkers will want to invest in the exceptionally good 1:25K Explorer maps available via ViewRanger.

    5. For all other countries -- ViewRanger offers National Agency maps for many European countries and may be the best option in those countries, however we do not know if other options exist and are therefore reluctant to suggest that ViewRanger is the best choice. Suggestions welcome!

  2. OpenCycleMap - aka, OpenStreetMap, OSM, OSM Topo, Cloudmade Topo/Cycle. Many iPhone apps include this map source because it is freely licensed topographic map of most of the world (below 60 degrees latitude). Although the topographic and geographic detail is not as good as maps from the national mapping agencies, there are three important characteristics: it is freely licensed; cultural information is often more current; and it covers most of world. Take a look at the OSM treatment at their website. We have successfully used OpenCycleMaps together wtih Satellite imagery (with no National Agency Maps) for long hikes in Turkey, Australia, and Spain. In Turkey there were no National Agency maps available; in Australia and Spain they were available but at too high a cost for our purposes. Gaia GPS is our favorite app for this map type. There are many other apps that provide access to OpenCycleMaps, but only Gaia (that we have found) also includes downloadable world-wide Satellite Imagery, is easy to use, supports waypoints and tracks, and allows import and export of gpx and/or kml files.

  3. Satellite images - Often very useful, especially for off-trail hiking. Gaia GPS is our favorite app for satellite imagery as it offers downloadable satellite imagery of the whole world (3 different sources: Mapquest, ESRI, Google), and also USGS Aerial Imagery for most of the CONUS.

  4. Regional and local maps - Nearly every park publishes a map, showing park boundaries, trails, roads, campgrounds, and points of interest. These will nearly always have the most current trail information.
    1. Maplets is a great app for viewing these maps; if the park you want is not already available, submit a request and they will attempt to add it. You could find these maps on your own, and view them using any iPhone pdf viewer. However, Maplets makes it very easy to find them, and by using Maplets you are able to see your current location on the map (assuming the map was drawn to scale). Maplets includes limited ability to import, create, and export tracks and waypoints, so you might end up using it in conjunction with a more fully featured app like Gaia GPS. (Of all the apps I've used, Maplets is the one I most wish I had imagined and then produced; it is an elegant, simple, useful, concept that is very well executed.)

P.S. Here is an annotated list of some of the non-mapping apps that were suggested by folks on the BackpackingLight.com forums.

Tips on Using the iPhone

Regardless of which app you choose, there are a few considerations for using an iPhone in the backcountry.
  1. Data - When you have a WIFI connection, download the map content (and trail data if you have it) that you’ll need while hiking. Your iPhone can get GPS signal in the woods, but you will be unlikely to reach the Internet for data.
  2. Battery Life - Manage your battery life. Day hikers can get away without taking special steps to tend the battery life, but for multi-day trips, you must tend to these things. This article closes with detailed instructions on how to maximize battery life.
  3. Protect Your Phone - In terms of waterproofness and durability, the iPhone needs to be treated as you would treat a non-waterproof camera, unlike a Garmin which is designed for outdoor conditions. A zip lock bag is a simple and cheap way to protect the phone in most environments; the best options are Heavy Duty Freezer Pint size or Aloksak 4.5x7". Even when it not raining, we keep the iPhone in a zip lock to protect it from sweat and dirt. Lifeproof makes low-profile light-weight completely waterproof cases, which we use when hiking in very wet environments.
  4. OpenStreetMap - Spend an hour learning about OpenStreetMap (aka OSM). OSM is a free map of the world, and many iPhone apps are based on map content from OSM. OpenCycleMap (aka Cloudmade Topo) is a variation that includes contour lines and hiking trails. Data is added to OpenStreetMap by users like us, wiki style. If your favorite trails are not there, then you can add them and the world will be a better place for it.
  5. Software Updates - Occasionally check for updated versions of your apps.
  6. GPS Accuracy - In theory the iPhone 4S and 5 should be more accurate than the iPhone 4 because they use both GPS and GLONASS satellites. When using the iPhone 4 in shallow grade mountains or flat landscapes, with minor tree cover, the accuracy has consistently been within 10 meters. When using it in deep steep walled canyons, the fix is not as accurate as Garmin, 50 to 100 or more meters off in a deep canyon (Paria Canyon in Utah). Using a Garmin and an iPhone 4 we concurrently recorded tracks on 12 miles of trail in fairly dense conifers on the west slope of California's Sierra Nevada range and could not tell any difference in accuracy. We leave it to the reader make their own determination if this level of accuracy is sufficient. We have not tested under heavy tree cover.

Battery Drain and Different Models of iPhones

When all battery conservation measures are in place (as per the Battery Conservation Settings section), the baseline battery drain of the best models of iPhones is 1-2% per day. By baseline drain, we mean that the phone is powered on, but asleep; it is ready for use, but the user is not actually doing anything with it. This is the background drain you will incur even if you don't take any pictures, look at any maps, or use any apps at all.

The Airplane Mode switch in Settings turns the Cellular Service AND the GPS chip ON or OFF. You can not independently turn Cellular OFF but leave GPS ON. To show your location in a mapping app like Gaia GPS, you must set Airplane Mode to OFF.

Sadly, when Airplane Mode is OFF, the iPhone, in some configurations, drains the battery trying to establish a Cellular connection. The amount of battery drain depends on whether you are in-range or out-of-range of the cellular provider. Therefore if you test your baseline battery drain at home you are likely to get one result (in-signal-range), while when you use the iPhone in the backcountry you will get a different result (out-of-signal-range). (In order to do my battery drain testing, I constructed a Faraday Cage by putting the iPhone inside a closed cookie tin and putting the tin into a microwave oven; neither the cookie tin nor the microwave alone blocked signal).

Summary: ATT iPhone 4/4S is great. ATT iPhone 5 is bad. Verizon iPhone 5 is great. Other models are untested.

  1. ATT iPhones 4 and 4S Baseline battery drain:
    1-2% per day: SIM Inactive (either locked or removed) (signal either present or absent).
    9-10% per day: SIM Active (signal present).
    30% per day: SIM Active (no signal).

  2. To maximize battery life of an ATT iPhone 4, deactivate the phone’s SIM by using one of two methods:
    1. Use the SIM PIN feature (read Apple's Help Topic. and call 611 from your phone to get your initial PIN from ATT). When using this feature, you are asked for the PIN code only after the phone is fully powered down, not after each time the phone has been asleep. This is an elegant easy-to-use solution that gives a great result.
    2. Remove the SIM card from your phone. Be careful, the SIM card is small and quite easy to lose. This method may work for any iPhone 4 with a SIM card, not just ATT phones in the U.S.

  3. ATT iPhone 5 - The baseline battery drain is completely different than the ATT iPhone 4, and the optimal configuration is exactly opposite the iPhone 4:
    8-10% per hour !!!!: SIM Inactive (either locked or removed) and signal absent. --- This is an egregious battery drain bug.
    ~8% per day: SIM Active (signal present).
    ~22% per day: SIM Active (no signal).

  4. To maximize battery life of an ATT iPhone 5 when no signal is present, you must leave the SIM active. If you lock or remove the SIM you will have a disaster when you leave signal range. In the best configuration, SIM active, the drain is still an unacceptable ~1% per hour. Therefore, if you are using an ATT iPhone 5 for backpacking, you need to change your practices to turn Airplane Mode ON between each usage of the GPS. If you forget to toggle into Airplane Mode, you will drain 1% per hour searching for the non-existent signal (which is better than draining 10% per hour which happens when the SIM is inactivated.)

  5. Verizon iPhone 4 or 4S? Sorry, I have not tested these.

  6. Verizon iPhone 5 - Baseline battery drain:
    1-3% per day: SIM Removed (no signal). Probably same result for locked SIM, but we didn't test this.
    1-3% per day: SIM Active (no signal).
    ?? not tested: SIM Active (signal present).

  7. The Verizon iPhone 5, based on our tests, will have excellent battery life in the backcountry with the SIM active or inactive! The Sprint iPhone 5 probably behaves like the Verizon iPhone 5 (the hardware is similar for those two products) but we did not test it.

  8. iPhones 5S and 5C, released in September 2013? Sorry, I don't know anything yet.

Battery Conservation Settings for Backcountry use of your iPhone

It's important to follow these guidelines to conserve your iPhone battery and get the maximum battery life in the field. For day hikes or overnight hikes most of these suggestions are not important, but they are critical if you want to use an iPhone for a multi-day trip without resorting to a recharge solution (external battery or solar). Our research ended up focusing a great deal on battery life, and we hope these ideas help:
  1. Adjust the Settings to optimize for battery life. This is a comprehensive list of settings that will enhance your battery life, some of these have significant impact and some have marginal impact. You might chose to ignore some of these changes if you value the service that is provided and can afford the associated battery drain. Some of the settings are new in iOS 7.
    1. Airplane Mode = OFF (while backpacking this must be OFF to make GPS work)
    2. WIFI = OFF
    3. Bluetooth = OFF
    4. Cellular->Cellular Data = OFF
    5. Personal Hotspot = OFF
    6. Notification Center - turn off notifications for all apps - No sounds, no badges, no alerts, no nothing.
      (This can be a hassle to undo after a trip; if you don't want to change all of your app notification settings, you could leave as is and do your own baseline battery drain testing to make sure it is still acceptable.)
    7. Notification Center - Down at the very bottom of Notification Center - Amber Alerts and Emergency Alerts = OFF
    8. General->About->Diagnostics and Usage = Don't Send
    9. General->Siri = OFF
    10. General->Accessibility->Reduce Motion = ON. Apple's Help Topic explains what this does. For more information see this article.
    11. General->Usage->Battery Percentage = ON
    12. General->Background App Refresh - This is a useful place, new in iOS7, where you can disable each app from doing work while it's in the background (i.e. not open and visible on the screen). Turn oFF everything that you won't need to have running in the background while on your trip. For example, you won't need the Stocks app trying to updated stock prices while you sleep! On the other hand, if you intend to turn on Tracking in Gaia, then you will need to have Background App Refresh turned ON for that app. Even though I rarely use Tracking while backpacking (due to battery drain), I have used it for short segments of off-trail hiking where I wanted to document our route./li>
    13. General->Date&Time->Set Automatically = OFF. This means that when you change time zones you will need to manually adjust the time zone.
    14. General->VPN = OFF
    15. Wallpapers & Brightness - Auto-Brightness allows the screen to adjust its brightness based on current lighting conditions. Or you can manually change it to meet your needs. New in iOS7, the Control Center provides very easy access to adjusting the screen brightness. A brighter screen is a significant battery drain, so to minimize drain you should make sure the screen is not brighter than necessary.
    16. Privacy->Location Services = ON
      Turn Location Services OFF for any app that you will be using while backpacking unless it is important for that app to have a GPS read. For example, if you use a Camera app and you want it to put a GPS stamp on each image, then leave Location Services on for that app. However, if you don't care about having a GPS stamp on the image, then turn Location Services off for Camera app so that it does not engage the GPS (and therefore drain battery) every time you take a photo.
    17. Privacy->Location Services->System Services (all the way at bottom of Location Services): Everything OFF, except possibly Compass Calibration ON. I couldn't find any documentation on Compass Calibration setting does, and when I tried to test the compass, including True vs Magnetic North, I couldn't figure it out. So you're on your own for that setting.
      Apple was very sneaky to hide these things so well. Few users would voluntarily drain their battery getting GPS reads so that advertisers can serve location-specific ads. Yuck.
    18. Privacy->Advertising->Limit Ad Tracking = ON
    19. iCloud->Storage&Backup = OFF. (This may not impact battery life, since in theory it only engages when the phone is plugged in; I include it here because the Genius Bar helper suggested that it might help conserve battery life.)
    20. Mail, Contacts, Calendars: Fetch New Data -> Push = OFF, and Fetch = Manually
    21. iTunes&App Stores->Automatic Downoads = OFF and Use Cellular Data = OFF
    22. Control Center -> AirDrop = OFF.
  2. Shut down all extraneous apps.
    The iPhone supports a form of multi-tasking or background processing, and you are not likely to know what’s running in the background. A few apps (for example mapping apps that have engaged the GPS in Tracking mode) can actually do work in the background and consume power. To be completely sure you don’t have anything consuming power, fully shut down all the apps you aren’t using.
    Here are instructions on how to shut down background apps.
    (For tech-weenies, here is an article that offers a more complete explanation.)
    iPhone 4 and Garmin Oregon 550t. The iPhone's display is larger with over six times the resolution of the Garmin. The map available on the iPhone has much better detail than the Garmin (pictured is a section of Alaska). In this picture the iPhone is in a one-ounce hard case with rubber shock absorbing liner. The case has raised edges of to protect the iPhone display from damage. The Garmin has a similar raised edge built into its housing.
  3. Don’t use the Tracking or Guide Me features.
    Most of the map apps have features to record a track as you walk, or to guide you to a specified waypoint. But to do this it must constantly get a GPS read, which is a steady battery drain. Instead, make sure you’re not in Tracking mode or Guide Me mode, and just get your current location when necessary. In our battery tests we found that Tracking mode consumes ~5% of the battery capacity per hour. If you do all the other battery-conservation steps, then you can use Tracking for a long day hike (~60% of the battery will be used in 12 hours of Tracking), but the Tracking feature is only viable for a multi-day backpacking trip if you have a battery recharge solution.
  4. Be EXTRA cautious about leaving the GPS app in the foreground during sleep.
    If Tracking is off and the app is in the background when the iPhone is put to sleep, none of the apps we tested incurred battery drain. However, if Tracking is off and the app is in the foreground when the iPhone is put to sleep, quite a few of the apps we tested incurred a battery drain of between 2 and 7% per hour (including, as of May 2012, X, GPS Kit, Trail Maps by National Geographic, and EveryTrail Pro). This is a significant issue and hopefully is a bug that the app’s respective developers will fix soon. Whichever app you choose to use, make sure you check to see if you must manually put the app in the background before putting the device to sleep, and if so, you must be absolutely diligent about doing so.
  5. Check to see if your apps give you control over when the GPS is engaged.
    Some apps have excellent battery management settings, most do not. For example ViewRanger and Gaia GPS have a setting that allows you to activate the GPS only on demand, whereas most apps run the GPS whenever the app is open. With ViewRanger or Gaia GPS, you can open the app and study the route without running the GPS, but still easily get your current location when you need it by tapping the Locate-Me icon.
  6. Beware of Auto-Lock.
    Under iPhone->Settings->General you’ll find Auto-Lock. After the user-specified duration of inactivity, the iPhone automatically goes to sleep as a battery conservation measure (since the display itself is a big battery drain). Of the nine GPS apps in which we tested Auto-Lock, four of them did not respect that setting, and the iPhone stayed on indefinitely if the application was in the foreground. Whichever app you choose, make sure you test to see if it prevents Auto-Lock from engaging and adjust your behavior accordingly.
  7. Keep the iPhone warm.
    Batteries achieve optimum service life if used at 20°C (68°F) or slightly below. Avoid letting the iPhone overheat in direct sun, and keep it in pocket close to your body in cold conditions. More detailed battery information in this great article.
  8. What to expect in the field.
    On a six week hike in Turkey Amy and Jim used the iPhone-4 15-30 times per day for 30 seconds to perhaps 4 minutes per use. Our battery drain was between 7% and 20% per day. The SIM was disabled, and we used all of the battery conservation measures listed above. We recharged in shops, and we were never more than 4 days between shops. On six week hikes in Australia and Spain, where we had more frequent access to shops and therefore less need to be frugal, we used the camera and reference apps in addition to map apps, and on these trips used 25-40% of the iPhone-4 battery per day. On a six day mostly off-trail backpacking trip in Yosemite Alan and Alison used the iPhone-4, and averaged 12% daily battery drain. Since switching to an iPhone-5, we our battery life is not as good as with the iPhone-4. We now try to remember to keep it in AirplaneMode=ON (with iPhone-4 it didn't matter), and even so the battery life is limited to about four days given our usage (occasional GPS reads, 10-20 photos, occasional use of bird guide apps, nightly journal entries, etc). Your mileage will depend entirely on your usage patterns, but these examples from different users in different circumstances give a sense for what you might expect. Prior to a multi-day trip, be sure to test your baseline drain (iPhone asleep and no activity) to make sure that drain is minimized as described in the Battery Drain section. And experiment on day hikes so you can estimate your daily drain based on your own usage patterns.

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