Before you can get your first stamp you’ll need a passport book. You can buy these online or at the visitor centers of national parks. There are Four different type of books; Junior ranger, collectors, classic and explorer. Each book comes with it pros and cons , I personally prefer the Explorer edition but which book would depend on your preference. you can look online at the different editions, The link here, Just note that some parks have more than one stamp associated with it so if you really trying to get every stamp know to man i’ll go with one what has compatible expansion packs like the classic expansion and explorer expansion , which are extra pages sold separately that can be added to a book.
Next you’ll need to know about the ink stamps themselves also know as cancellation stamps. The stamps are located at the visitors centers or point of interest like campgrounds. Stamps will have the names of the parks, the location, and the date.
And finally the sticker stamps also know as Affix Reginal stamps. They are an annually sticker page show casing a park from each region and one national stamp. The sticker set go as far back as 1986, and can be bought online here or picked up at gift shops or visitor centers these stamp go in the grey boxes in you passport books.