We have recently returned from a trip to Arizona, Utah, etc....and used my Golden Age passport at both Zion and Bryce Canyons in Utah as well as Walnut Canyon in AZ. There were absolutely NO issues at any of the sites. The ranger at Walnut Canyon did ask for my DL for ID, but the others just waved us through as I held up my Passport card. I did notice the posted signs that had either a $30 or $35 per car admission fee for everyone else.

This trip was in April, of this (2018) year, so that's fairly current. There had been an earlier proposal to charge much higher admission fees, but the outcry about that seemed to make the administration have a change of heart. My view is that a fee in the $65 range would mean that a LOT of people of limited means would not be able to appreciate the amazing sights in these wonderous places...