I have a similar (or same? I got it over a decade ago and things change) pass for disabilities from military service. One flash of it and my driver's license and I get access to every single park and half off camping. I've only gotten grief once when a campground manager did not believe I was old enough to be disabled. I straightened him out pretty quick. Entry fees aren't expensive per se, but I have certainly saved a good amount of money. It makes quick trips to my local national monument more likely when I don't have to fret over visiting for just a few hours.