Gps didn't work in Yellowstone

Gremlins? Magnetic interference?

Did your unit start working as soon as you left the park?

I've used my Garmin 3490 all throughout most National parks & Yellowstone without issues.

Going to Yellowstone and Mount Rushmore in July.

I wonder....

and had no issues at all with my Garmin. I've never had problems with it anywhere and I've traveled a lot with it various parts of the US and Canada - never a single issue.

I think there are GPS dead spot in Yellowstone. I went there 4 years ago with my GPS.

I had heard the same thing about a lot of areas in Yosemite but covered most of the entire parks roads including the valley areas back in 2009 and my 885T never had a problem finding the sats anywhere I went.

No issues whatsoever with my nuvi 500.

I suppose the reason might be that the GPS could not see the satellites?

...sequestration. GPS is turned off over all large federal land tracts that do not have an airport within the boundary. (bad joke)

I'm wondering why it didn't work there. Lots of visitors and employees use GPS.

I was there a few years ago with a 1690 and no issues.

While the government could create a GPS free zone using jamming transmissions, I'm sure they don't actually do that for Yellowstone--and if they did there would be NOTAMs active (as there often are for a location where they test such things centered on the TorC VORTAC here in New Mexico. There can't otherwise be an actual dead spot. However anywhere at all that you are, you can have GPS trouble by blockage of the view of satellites. Urban canyons may be the most familiar case, but tree canopy of even very modest thickness attenuates the signal enough to defeat successful transmission even with modern receivers. It has been a long time since I have been in Yellowstone and I don't know just where the people complaining of Yellowstone GPS problems were spending their time, but my personal guess is that if there was any real problem at all, most likely it was signal blockage by trees.