It's a program that's been around in North Dakota since 2013 so it's worth a reminder.

If you have a library card to a public library in the state or to the state library, you can rent out a pass to use at North Dakota state parks the same way you would rent out a book.

It's called the Library Loan Program.

There are 14 different state parks scattered across North Dakota that normally charge a $5 vehicle fee. But you can of course get a library card for free, and if you rent out a pass from the library (which is also free), you can get into the state park for free.

It should be noted that the library pass only waives the $5 vehicle fee. If you choose to campout or rent a cabin, those fees still need to be paid.

Also you have to go to your local library and rent out a physical pass. You can't just show your library card at the park entrance. The passes are good for seven days.

Find more information here and here