While the main attraction is underground at Mammoth Cave National Park, there's quite a bit to see, enjoy, and learn from above ground at the Kentucky-based park. To preserve that setting, park crews are battling invasive trees that, if left unchecked, could pose a deadly threat to the native hardwood forests.

Good teachers are on the lookout for opportunities to expand their knowledge, and it would be hard to find a more appealing "classroom" than Alaska's Denali National Park in the summer. Teachers can apply now for scholarships for seminars and training in the park next summer.

Ahhh, the sun-kissed Caribbean. Is there a better place for a mid-winter's getaway than one with sugar-sand beaches lined by palms and washed by warm turquoise waters that provide habitat for turtles the size of trunks, colorful fishes like blue tang and parrotfish, and menacing barracuda? If you don't think so, then Virgin Islands National Park is your destination.

A succinct, four-paragraph memo from National Park Service Director Jon Jarvis two weeks ago spurred an outpouring of comments from Park Service employees and marked, potentially, a sea change in how park superintendents go about budgeting for their parks. But is it something the general public should take note of?