Our public lands protect resources that belong to everyone yet some people decide to steal our resources for their own personal enrichment—robbing this and future generations.

A carefree New Yorker who left acrylic calling cards on the landscape of at least 10 national parks is just the latest vandal to "show-off" her work via Social Media channels. Another scofflaw recently entered a guilty plea to illegal behavior in Yosemite National Park that he, too, showcased via Instragram, a form of self-promotion that provided investigators with the clues they needed to land a conviction.

Xanterra Parks & Resorts, which operates lodges and restaurants in some of the most iconic national parks in the system, on Wednesday announced it was suing the National Park Service over its handling of concessions contracts on the South Rim of Grand Canyon National Park.

Geology factors into many units of the National Park System, but there are some parks that rise above all others if you have an interest in the geologic past...and present. What follows is a short list of some of the most geologically fascinating parks in the system, though we're sure you can add others.