For those stumbling across this page via a search, this document covers installing custom maps and data files used by rural fire departments for emergency response. While this information would apply to any files of those data types, this is primarily focused on the maps I produce. Those are available on my Fire District Maps page. For hiking and climbing maps and data, go back to the top.
For many apps these following steps may be unnecessary. Most mapping apps will let you browse online sources and cache the basemaps and other data, letting them work offline. The downside of that is you have to actually browse each app to the areas you want, and pan around at various zoom levels to get everything. That's fine for an end user, but not practical for those of us maintaining multiple devices. Course if you know you will always have a cell data connection, you probably don't care. I spend much time without a cell connection, so utilize disk based files instead. Also for large map files, the download time can be lengthy.
Many mapping apps for IOS or Android let you specify OpenStreetMap as an online source. For my local area (Gilpin and western Boulder County), the data in OSM is reasonably complete and well validated, less so in other areas. Improving that is a long-term work in progress.
What works for for all smartphones and tablets is to simply download a file, and after the download is complete, you are usually asked what app you wish to open the file in. If you don't get asked, change your device settings to not have a default for files of that type. The advantage of having multiple disk files downloaded is you can use then when you need to, but they aren't sucking up all the memory in your mapping program, making it unbearably slow. I keep all the maps for other areas I visit occasionally, but aren't loaded into any app until I need them, since I'm often without a cell connection.
If you download a GeoPDF file off this site, use the Open button on the lower right corner of the browser window to open it in Avenza. You can also specify the URL for a data file and Avenza will download it and install it for you. KMZ/KML data files can be loaded the same way. This is tedious if you maintain a large collection of devices, and often setup several devices in batches.
You can also import already downloaded files. Using the menu on the bottom of the screen, to import a map, click on My Maps, and then the plus sign. That'll ope the dialog box to enter a URL to download a map, or import from local storage. To import a KMZ file, click on Layers, and then horizontal line menu button.
Please note that according to the Avenza license, you are limited to using the free version for only recreational use. They explictly do not allow Avenza to be used for emergency response, and it comes with an annual fee over $100USD. Some states and organizations have purchased group licenses, so please be concious of your usage. Personally, I find Avenza's functionality limted when compared to the other mapping appilcations discussed here.
KMZ files are useful because they're so portable. They work in most all mapping apps, on the desktop, and work in Google Maps and Google Earth as well. You can get KMZ data files from my Colorado Fire Districts page. There are two types of KMZ files. Most of them contain waypoints and roads and trails. This data is searchable, and the various layers can be turned on and off to de-clutter the display. The other type are full of polygon data, and have no display name. These are focused on where am i? type of data. Click on the polygon and the popup will contain information, like parcel owner, or fire district boundary. There is an attempt to color code the parcels to delineate between public and private property.
I manually copy data files for Android devices, cause I don't always have an internet connection. In that case rather than clutter up the Downloads sub directory, I put them in an easy to find location so I can load the same data files into multiple devices. On our most devices, these files go on the internal SD Card at /storage/emulated/0/KMZ. If you have a large external SD card in your device, you an use that instead, which uses a path like this: /storage/[UUID]/KMZ.
While the KMZ files contain all the icons, not all apps seem to honor them, Google Maps and Google Earth among them. The default icon set in these is not sufficient for emergency response. Luckily you can manually add custom icons, but you just have to actually go do it, or all you get is a screen full of X marks. Sorry. A KMZ file is just a zipped KML file, so if necessary you can unzip it to extract the icons.
For road navigation that works offline. I've standardized on the OsmAnd app instead of the current Maps.ME, since it's available for both Android and IOS, and works fully offline. Maps.ME uses the same data, but has a simpler user interface which some people prefer. Both apps will let you download an entire area or state, and then it works offline. For example, if I download the latest map for Colorado, it'll have all the same data I use to produce KMZ data files. The nice part about doing it this way it you'll get occasional updates of the map.
On an Android tablet, these files go on the SD Card at /sdcardAndroid/data/net.osmand/. The obf file is the same data as whatever you would download via the app, but often for me, reduced in size, or a custom area. The sqlitedb files are for Alpine Quest.
For an iPhone or iPad user, you're stuck downloading them and using Open In to import them.
Then click on the menu, then Configure map. Under that you can specify offline vector maps which will use any obf files you've downloaded. For the basemap, under map source enable the Underlay map option. Then click on the default map name, and it'll popup a menu with all the basemaps you've downloaded.
To search, start typing the road name in the search bar, and it'll pop up all the addresses on that road. Select the one you want, then click on the 'Directions' icon, and off you go... This has all the various road names, ie... Pewabic Mine vs Pewabic Mountain vs Druid Mine roads. Directions have optional audio output, pick your favorite.
For Android users, a more back-country oriented GPS program (as opposed to road navigation), is Alpine Quest. Install that, and download the basemaps (*.AQM) from my web server. You can then install the KMZ files into AlpineQuest. IOS users can use GaiaGPS, but then you have to pan around and cache the online map data. The free version of Alpine Quest limit functionality. If that drives you crazy, the pro version is relativily cheap.
Once downloaded, these files go on the SD Card at /storage/emulated/0/Android/data/psyberia.alpinequest/files/, which should then look like this:
Once you get everything installed, you can try viewing the presentation I did for our training class. The presentation is here, and the short handout of steps to go with the screenshots here.