The Yellowstone Plateau Volcanic Field has some of the largest rhyolite lava flows on Earth. Have you ever wondered what these flows look like in their interior, or how the unique textures that can be observed in rocks across Yellowstone National Park formed?

Drive 75 miles (121 kilometers) from busy Washington, D.C. and you’ll enter 200,000 acres (>80,000 hectares) of protected geography rich with history and the ghosts of Civil War soldiers vying with songbirds and waterfalls to tell their stories. Shenandoah National Park in Virginia is a landscape of ancient mountains, rolling hills, shadowy backwoods, and quiet hollows.

Efforts to blunt the ferocity and destruction of wildfires are dividing conservation advocates over proposals that would sidetrack science and allow for less analysis under the country’s hallmark environmental law. Critics fear that approach could accelerate unnecessary logging in national forests.

There are so many things making up the story of a unit within the National Park System, including plants, animals, and historic buildings. This month’s National Parks Quiz And Trivia edition focuses on some of the vegetation you might see during a national park visit.