As you navigate the incredible diversity of the United States national parks, prepare to create memories that will last a lifetime. Your next great adventure starts here.

While hundreds of parks are free to enter, others use timed entry and other reservation methods to control crowds — but that also means you may need to secure your spot well in advance.

Newly released data shows that US national parks welcomed a record number of visitors last year. Yet park advocates are warning that the visitor experience is now under threat. Following last ...