And the price is increasing from $30.00 to $70.00:
https://www.bozemandailychronicle.com/news/environment/national-park-service-proposes-raising-yellowstone-entrance-fee-to/article_3b840ea6-8a5e-5610-adf6-dba4891f1290.html
They're proposing $75 for Rocky Mtn National Park.
Says "The National Parks and Federal Recreational Lands Pass" Some other small print I cannot quite read.