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Big Sur Trailmap for Smartphones
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Note:  I do not have hiking experience with a smartphone, since I do not own one.  Information presented here is based upon experimentation with GPS apps on a friend's iPhone, so is likely incomplete.  If you think something needs to be added, post to the Trailmap Forum to educate me and I will add that information to this webpage. 

Smartphone vs GPS info

App map warning:   Smartphone apps generally use USGS or OpenStreetMap derived topographic maps. both of which have incorrect or incomplete trail and camp locations in the Ventana/SilverPeak wilderness areas.  So the focus here is on apps which can use the accurate Big Sur Trailmap data I provide.  (FYI: for Big Sur trails, all commercially printed Big Sur maps are more accurate and complete than those in smartphone apps which use USGS or OpenStreetMap maps.)

Note:  much of Big Sur has no wireless phone reception, especially in the wilderness, so requires a GPS-enabled smartphone and "off-line-map" software - all software described below has that capability, but some are easier to utilize.

Trailmap GPX File in GPS App

Many, but not all, smartphone GPS apps can import a GPX file to display lines ("tracks"), such as trails, and points ("waypoints"), such as camps.  With such apps, you can add the Big Sur Trailmap lines and points, i.e. trails, camps, water sources, etc., by importing this 2.3MB GPX file.  Note: it does not contain "lost" trails or camps.  (The file's copyright restricts it to personal use, i.e. it is not to be promulgated to a public source such as AllTrails or OpenStreetMap or Gaia Cloud - as these abusers have.)

This method's advantages are:
    • no cost
    • availability in most smartphone GPS apps
    • trailmap lines and icons are always on the phone, even outside internet coverage;
    • tapping on trail/icon will display associated info (on most apps)
Disadvantages are:
    • mixes trailmap lines and points with all other lines and points you have in the app
    • displays trailmap line colors and icons differently from the on-line trailmap
    • updating may require deleting existing lines and points before exporting new trailmap file
      (depends upon whether app overwrites or re-names trails with same name)

I've found these links giving GPX import instructions for MotionX and Gaia
(but MotionX or Gaia users may want to instead use the Trailmap Tiles in GPS App method described below)
   Gaia GPX import instructions
   MotionX-GPS GPX import instructions
If you know a link for instructions for another app, let me know and I will add it here

Abusers:  Gaia provides a "cloud" into which some users have uploaded my copyrighted GPS files - some having uploaded all my data by using the file linked above!  Gaia "cloud" disseminates it publicly.  So far, I've found the following Gaia users who have made such uploads, abusing my trust in making my data available for others to use (and necessitating time and effort from myself and Gaia to remove them):
       Adam Stepanovic
       Ken Toyoma
       Jake Rice

Trailmap Geospatial PDFs in GPS App

Avenza PDF Maps app (for android and iPhone - free for 3 loaded maps, $30/yr for unlimited loaded maps) can display geospatial PDF maps such as the single-page-printable PDF Trailmap sections, in addition to on-line maps, by downloading each map.  Many find this app simple to use and fits their needs when they just want to know where there are on a map. 

This method's advantages are:
    • free if willing to load/unload maps as need be pre-hike (so only 3 loaded at one time)
    • displays trailmap lines and icons just as on the on-line trailmap
    • trailmap is always on the phone, even outside internet coverage;
    • allows trailmap to be easily enabled or disabled
Disadvantages are:
    • must change maps when moving from one section to another
    • multiple downloads required if expect to move from one section to another
    • updating requires uploading the latest trailmap PDF files

Garmin Trailmap in GPS App

OruxMaps app (for android - free) can display Garmin-format maps such as the Garmin-format Trailmap, in addition to on-line maps, by copying a map "img" file to the default offline Oruxmaps folder "oruxmaps/mapfiles".  A user reports that this process worked successfully for a Big Sur Trailmap Garmin-format "img" file.  More instructions are provided in the manual and tutorials

This method's advantages are:
    • no cost
    • displays trailmap lines and icons just as on the on-line trailmap
    • trailmap is always on the phone, even outside internet coverage;
    • allows trailmap to be easily enabled or disabled, with a single click
    • tapping on trail/icon will display associated info
Disadvantages are:
    • updating requires uploading the latest Garmin-format trailmap file
    • map creation requires additional user knowledge and time and effort

Trailmap in Smartphone Browser

A smartphone browser can display the Big Sur Trailmap in its browser versions: Trail Conditions/Trailmap and Gmap4.  However their use generally requires one to be "on line", i.e. within cell phone reception.  In theory, they can be used "off-line" by (pre-hike) moving the map along a desired route with the map at the desired resolution, which stores those map images ("cached") - but this is difficult to setup and tricky and the phone then cannot be turned off.  The Gmap4 creator has developed detailed instructions of the necessary procedures, available here.  Differences between the two versions include display of trail conditions by the former and greater (doubled) topo map resolution by the latter. 

The browser method's advantages are:
    • no cost
    • displays trailmap lines and icons just as on the on-line trailmap
    • latest map is automatically provided when within internet coverage
    • availabile in all smartphones
    • tapping on trail/icon will display associated info
Disadvantages are:
    • off-line setup is difficult
    • phone must be left on after map download

Trailmap Map Tiles in GPS App

Smartphone GPS apps, such as Google Maps, typically display maps produced by a map tile server, accessed via the internet.  (Tiles are small pieces of the map.)  Since only map tiles around the active location are kept ("cached") on the smartphone, this saves memory - but when internet access is lost, only currently cached tiles can be viewed.  For wilderness use, the below apps circumvent this problem by allowing a specified area to be downloaded and stored, so the map can still be displayed when internet access is unavailable. 

Some smartphone GPS apps, for example
      MotionX-GPS (for iPhone & iPad - $7 with upgrade)
      Gaia GPS (for android & iPhone - $20/yr)
allow one to choose any map tile server as a map display.  For users of those apps, I've created a tile server which displays Big Sur Trailmap lines and icons on a USGS topo background. 

This method's advantages are:
    • displays trailmap lines and icons just as on the on-line trailmap
    • allows trailmap to be easily enabled or disabled, with a single click
    • latest map available when within internet coverage
Disadvantages are:
    • not free
    • availabile only in some smartphone GPS apps
    • trailmap must be stored prior to use outside internet coverage areas 
    • image only - tapping on trail/icon will not display any info

Big Sur Trailmap tiles only cover the Big Sur region - outside there, blank tiles will be displayed.   Also, only zoom levels 6-16 will be displayed.

MotionX-GPS has a "custom map" feature for displaying a user-specified tile map.  To create a custom map, select "Setup", "Custom Map", "New", then follow the screens for loading a new custom map (including purchasing a $7 upgrade).  The url input needed for the "Big Sur Trailmap" is "[Z]/[X]/[Y].png" - and turn storage of downloaded maps "On".  For more info see this link or this video tutorial.  After setting up the custom map, you must go to "Maps""Map Catalog""Custom" and touch "Big Sur Trailmap" to make it the displayed basemap.  And to display when out of internet/phone service, you must download the tiles to your phone - read the "Map Downloads" section of the MotionX manual for instructions.  To see what the Big Sur Trailmap basemap should look like on MotionX, see the "Example Tile" below.  Note: the MotionX implementation allows zooming in beyond the maximum tile zoom level, producing a gray-tile screen from which one must unzoom - hopefully they will later allow a maximum zoom level to be specified, as Gaia does. 

Gaia GPS users can add the Big Sur Trailmap to your "Layers" (per Gaia support) by  clicking on this setup link from your device After clicking the above setup link, you must go to "Layers" and touch "Big Sur Trailmap" to make it the displayed basemap.  And to display when out of internet/phone service, you must download the tiles to your phone.  To see what the Big Sur Trailmap basemap should look like on Gaia, see the "Example Tile" below. 

Technical details:  (needed for use by other apps):  tiles are accessed at subdirectories of, providing 256x256 pixel PNG tiles with directory ordering "ZXY", Y increasing southward (i.e. GoogleMaps/OSM/XYZ format, not OSGeo TMS), for zoom levels 6 through 16 (zoom6-13=100Kmap,zoom14-16=24Kmap).  Bounds are 35.758° to 36.415° latitude and -121.874° to -121.162° longitude.  The top-most tile is   A GeoJSON tile information file is available here.  Storing the complete tile set requires 400MB of memory.  April 2017: added links so now also accessible using OSGeo TMS ordering, i.e. Y increasing northward.

Overlay Tiles:  If overlay tiles, i.e. just trail/road lines and feature icons on a transparent background, are desired, they can be obtained ala the above information but instead accessing the subdirectories at

Example Tile: below is the highest zoom (level 16) tile covering the Big Sur Station and Pine Ridge Trail trailhead (36.24689°N,121.78047°W).  Note the "building" icon, green trail lines, blue 0.2 mileage between blue dots, etc., with a USGS topo map underneath.  In short, the map should appear with trail/usetrail/road line colors and camp/water/summit icons all ala the printable Big Sur Trailmap, which is ala the on-line Trailmap with the addition of distances between blue dots (when over 0.1 mile)
example tile

If you know of other GPS apps which can use this tiled map, let me know and I will add that info here. 

The tiled map is new - if you encounter a bug or have suggestions, let me know.  In particular, I can alter the size of the lines and icons if need be, but if requesting that please include the smartphone type you are using, so I will know the screen resolution being used. 

Smartphone vs GPS

In my view, smartphone maps are a "middle step" in a heirarchy:
    • paper maps
    • smartphone maps
    • GPS maps

Smartphone maps offer advantages over paper maps, particularly being able to show your location on the map and to zoom in/out - but also have some disadvantages, notably showing only a small section of the forest and depending upon a battery.  In turn, GPSes have features not in smartphone maps, such as their abilty to depict differing detail at differing zoom levels and to compute "along-trail" distances - but also disadvantages, notably a steeper learning curve and needing to purchase/carry an additional piece of equipment.  My current thinking is that those wanting an "electronic map" and owning a smartphone should first utilize a smartphone app - it may well meet all your needs.  If you later want a more capable "electonic map", you can step up to a GPS.

    Smartphone apps use a "raster" map whereas GPS's use "vector" maps.   Each has advantages/disadvantages..  App maps tend to be prettier whereas GPS maps have additional capabilities useful for hard-core map users.  As a bushwhacker, I find a GPS has advantages as an "electronic map", some of which I'll list here since many have not used vector maps: 
      • provide different details depending upon the zoom level  (eg: stream crossings are shown at higher zooms)
      • display constant line widths and text/icon sizes at all scales, down to scales as small as 40 ft
      • give the elevation value of a contour line when you place the cursor over it
      • give the name of a trail, stream, etc. when you place the cursor over it
      • give along-trail distances between points
      • can be operated with one hand while hiking (for a "button style" GPS)

    While working on this page I came across
a comparison of smartphone app vs traditional GPS, which gives useful options for getting around smartphone limitations of poorer battery life, poorer gps accuracy, and poorer ruggedness.  Unfortunately it also tries to sell instead of being objective (since it promotes a smartphone app) and some assertions are incorrect - for example, Garmin users are not "locked into expensive, proprietary Garmin formats" since there are many free Garmin-format maps available on the web (apparently the writer never heard of  I've also found this detailed discussion of battery saving procedures.

    Of course, a fundamental difference and advantage of a smartphone is its non-map features (e.g. using the internet, making a phone call, using a plant identification app, etc.).  This seemingly follows the general rule (as I've experienced with airplanes) that one often must choose between something which can do a specific task very well vs. something which can do more tasks but is not quite as good for a specific task. 

Jack Glendening
Trailmap Forum