"no map data"

[trailsprinter]

Hiking in the Mogollon Rim area of northern Arizona...when I get south of 34 deg, 30', 0" the GPS screen becomes void of all contour lines and other data and I get a message on the screen: "no map data".  I can still set waypoints and follow a breadcrumb trail, but no map features are available.

Why is this?

I did notice on a standard paper topo map that the contour lines change interval levels at this point.

[Boyd]

What map are you using? How did you install it? Does the same spot look OK in Basecamp on your computer?

[trailsprinter]

Boyd, thanks for the reply.

I'm using the free Arizona Topo map downloaded from this website (gpsfiledepot.com).

The Basecamp map contours, landmarks, features, etc. all appear normal.  That's why I was initially surprised when I got to my hiking starting point and realized I had no map data.

[Boyd]

This map? https://www.gpsfiledepot.com/maps/view/1/

I don't have any experience with this, but it was created by the site administrator here, so hopefully he will respond. You could send him a PM: https://forums.gpsfiledepot.com/index.php?action=profile;u=1

What you describe could happen if you did not install the entire map on your GPS (MapInstall and Mapsource allow you to choose how much of the map to install).

It could also happen if there is a problem with the way the map was created.

It could also happen if you install too many maps on your GPS at the same time. Garmin units have a limit to the number of map segments they can access (these are the small "tiles" that make up the whole map). If you exceed this limit, some parts of some maps may not work. The problem is specific to the exact maps you have installed so it's impossible to say exactly what will happen.

Older handhelds only access about 2000 map segments. Newer models typically can access about 4000 segments. These are the total of all maps installed on the GPS, regardless of whether they are in internal memory or a card. There are not standard segments sizes, that's up to the mapmaker.

But, for example, if you install one of Garmin's own 24k maps, you will already be close to the segment limit typically.

What GPS are you using and what other maps are installed?

[trailsprinter]

Etrex Venture HC.  An oldie.

Yes, that's the correct map and it's the only one installed on my unit.

[Boyd]

I believe that device only has 24MB of internal memory and does not accept memory cards, right?

https://buy.garmin.com/en-US/US/into-sports/discontinued/etrex-venture-hc/prod8707.html

24MB is not very much memory. It is quite possible that you can't fit the whole map into the unit, and it may be just chopping off something unless you have specifically selected a portion of the map.

MapInstall lets you do this, but for an old unit like yours, I would use Mapsource, Garmin's older software. This tutorial shows how to select an area of the map and send it to the GPS with Mapsource

https://www.gpsfiledepot.com/tutorials/how-to-load-maps-on-my-garmin-gps-unit/#mapsource

If you don't have the program, you must use a trick to install. Prepare your computer with GMTK first: http://www.javawa.nl/gmtk_en.html

New PC? Use JaVaWa GMTK first, then install MapSource

When you use JaVaWa GMTK to transfer maps to a new PC it is higly recommended to do this before installing MapSource. The downloadable version of MapSource is an update version, that refuses to install when no older version exists. JaVaWa GMTK prepares, when necessary, automatically your PC so that MapSource will install properly.

Then install Mapsource from here: http://www8.garmin.com/support/download_details.jsp?id=209

[Boyd]

Sorry, left out an important detail. When you select an area of the map in Mapsource, look at the Map tab on the left side of the screen. This will list all the segments you have selected along with their size.

Make sure you keep the total size less than 24mb, so that it will fit in your device's memory.

[trailsprinter]

Thanks again, Boyd, I'll give all of this a try.  This all will work on a Mac, right?  That's what I have.

[Boyd]

No... it helps if you mention that kind of thing in the beginning. 

You will have to use Basecamp/Mapinstall. Mapsource only runs on Windows.

I don't recall whether MapInstall tells you how large a map you are sending, but you can choose an area smaller than the whole map. When your GPS was made, Garmin did not support the Mac at all. Basecamp is supposed to support these older devices, but there may be some issues.