Garmin GPS 24k-level maps: free!

[Jonathan S.]

Okay, maybe everyone already knew this, but until now the big downside of Garmin GPS units has been the topo maps. The U.S. topo CD covers the entire country and is reasonably priced, but the contour intervals are really lacking. The nat'l park CDs are pretty good if they cover where you ski (and fortunately the entire AT corridor counts as a "nat'l park" for the eastern CD), but if they don't cover where you ski, you've been stuck with the 100k-derived nat'l CD.
Garmin has started to cover other states with 24k-derived detail:
http://www8.garmin.com/cartography/t...ous24kcard.jsp
. . . but available only on micro SD cards, which means you can't combine different states or map types (e.g., city navigator & topo) on one card, you can't view the maps on a computer, and you'd better not lose that super-small card. Plus the price would really add up if you ski in multiple states.
I had read awhile back that some Polish software whiz had reverse-engineered the Garmin code, and I saw some downloadable maps, but not much. Various website had instructions for using free gov't data to create your own maps, but looked pretty involved.
Yet now pretty much every western state is available, all referenced from one website:
http://www.gpsfiledepot.com/
And for free too. (Except for the WA map, which is currently $80.)
Checking out the forums briefly, looks like other maps should be coming up soon.
I've downloaded several states and viewed them from within Mapsource: pretty much comparable to the areas that Garmin covers with 24k-derived detail. (And when I toggled back-and-forth between Garmin 100k topo and the freebie 24k topo, the differen was striking.)
I'm still a big believer in bringing along a printed map (on waterproof paper, from software like National Geographic that scans USGS quads), along with a traditional sighting-mirror magnetic compass, but these third-party hobbyists now seem to be bringing out the full potential in Garmin's GPS units.
(And anticipating running out of space on my current 1 gig card, I bought a 2gig for only $8 including shipping from newegg.)

[upallnight]

good info, jonathan.

i've always been disappointed that the garmin maps were vector-based, although it makes total sense for portable device use vs. the flat graphics that are the nat'l geographc TOPO series of maps.

that said.... is there any way to know if we're dealing with derived 24k maps from garmin vs the actual 24k maps?

i have the garmin topo dvd, and i also have nat'l geo TOPO maps for the states where my adventures are centered.

i was able to load pretty close to the entire set of garmin topo maps for the USA onto my micro-sd card.... but i want to ensure i've got the most accurate detail.

any way to tell?

(i'm not at home, but later this weekend i can download and compare. i'm just a bit curoius in the meantime.)

thanks!

[Jonathan S.]

The freebie maps are generally the equivalent detail of Garmin's National Park series, so derived from 24k-level USGS data, but the rendering is far different.
However, contour lines are usually at 40 feet, which alone is far more helpful than Garmin's U.S. Topo series.
The details do vary by state, because as the fine print indicates, many of these are works-in-progress, so definitely check for updates.
For example, I compared Garmin U.S. Topo vs. Freebie for Wasatch: Freebie was superior in every way.
At Lassen, Freebie matched Garmin National Park contours, but lacked place/feature names, although contours were comparable (which are poor in U.S. Topo). I suppose this is to be expected given the huge job that the Cali map maker faces!
Back home in Mass., for Mt Greylock, Freebie has all the place/feature names but for some odd reason has 50-foot contours (instead of 40-foot), whereas for some other odd reason Garmin National Park has 20-foot contours. (And no, Mt Greylock is not the latest addition to the National Park system, but the AT crosses it, hence Garmin's inclusion in its National Park system, given how few national parks we have out here.) And U.S. Topo would have only the usual widely spaced contours (although I can't verify this right now, since Mapsource is no longer recognized my East CD for U.S. Topo).
I expect these freebie maps will improve over time (as well as eventually cover all states), but they'll still be vector based.
By contrast, this utility allows raster maps to be shown on Garmin units:
http://moagu.com/
My wife does GIS work for a living, so I'm going to experiment with some areas to see if she can display them on my GPS.

[The Reverend Floater]

Thanks, Jonathon. Not any Idaho topos, though...got any other ideas?

[Jonathan S.]

Idaho is coming up soon:
http://forums.gpsfiledepot.com/index...30.html#msg230

[Jonathan S.]

Idaho now available.

[Jonathan S.]

Update -- so for Idaho, Oregon, and Washington -- install this:
http://www.gpsfiledepot.com/maps/view/134/
I overlooked it initially since the documentation was pretty sparse, but it has 20-foot contour intervals, which is better than the single-state maps others have posted. Better than most of Garmin's own 24k-level maps for national parks too. Takes a long time to install, but given the 20-foot contours and huge geographical extent, hardly surprising.

The one drawback is that it doesn't show trails, but this:
http://www.switchbacks.com/maps/NW_Trails.html
... has better trails than any other maps. Within Garmin Mapsource, you can't view both these trails and the top maps, but on your gps unit you can view both layers simultaneously.

Note that for Shasta, the NW map also dips down into California a bit, but this map seems to be better:
http://www.gpsfiledepot.com/maps/view/28/

Also, for the Sierra, a true raster-based map is available:
http://www.gpsfiledepot.com/maps/view/143/
... which would seem to be the first raster-based map available on a Garmin GPS.

But based on my frustating experience just now, and then reading this:
http://forums.gpsfiledepot.com/index...pic,242.0.html
... I don't think the easy installation method is available yet within Garmin Mapsource.

Overall, amazingly what a bunch of random people have done in their spare time over a period of several months and given away for free, as compared to what Garmin did over many years (i.e., very little) at very high retail prices.

And yes, the usual caveat that this is not a substitute for a paper map (whether a traditional true paper map or a custom map printed out on waterproof material from scanned USGS quad software), but it's still very useful (and free -- well, with the purchase of a GPS, but a Garmin Legend HCx is quite affordable and is really all you need).

[jfost]

great work! I will try out some of these on my rino 530 and report back...

[likwid]

i've always been disappointed that the garmin maps were vector-based, although it makes total sense for portable device use vs. the flat graphics that are the nat'l geographc TOPO series of maps.

Flat graphics are terrible.
They load slow, you're stuck with either too little or too much data (no data scaleability). You have no ability to control WHAT data you want.

[Yukonrider]

Got mine for Michigan! Thanks great link!

Havent tested the accuracy yet, but it looks like its pretty close.