If anyone is interested, the Senior Lifetime Pass to US National Parks will be going up in price in late August. It is currently $10 (plus $10 processing), and will be going up to $80 next month. If I read this right, it is valid for the pass holder and those accompanying in a single vehicle. Not all parks charge a fee, but this would be handy to have imo. You have to upload an identifying document with the application (DL, passport, state ID). I just took a pic of hubs driver's license, and uploaded that. We may never use it, but I hope we will.
Here's the link: https://store.usgs.gov/senior-pass
eta - 'Senior' is 62+