The National Park Service has a new app that's intended to cover all the units of the National Park System, but that's a tall order for parks that lack staff to provide robust content.

When you go on a wild cave tour at Mammoth Cave National Park, shimmying around on your hands and knees, you'd never think to watch for sharks. Nor when you explore Petrified Forest National Park and marveled at the rock-solid slabs of wood, you won't sense a need to watch for any burrowing reptiles. But, as it turns out, those creatures did live in those landscapes...once upon a time.

Continuing a series of national parks quizzes and trivia, contributing editor Rebecca Latson wants you to try your hand at Quiz #3 to see just how much park knowledge you possess before checking the answers at the bottom of the article.

A project to rebuild the Green River Ferry ramp at Mammoth Cave National Park in Kentucky is taking longer to accomplish than anticipated, which means the service won't return until spring.