The recent spell of unusually cold weather in South Florida triggered widespread fish kills due to cold water. Biologists are studying the impacts on Everglades National Park. One thing they already know is that the rotting fish are going to stink for a while.

Walking through many national parks in winter can be tricky. In Yellowstone National Park, for instance, the boardwalks through geyser basins can be snow-and-or-ice-covered, hiking trails in Grand Canyon National Park can be icy, and trails in countless other parks that experience snowy winters can be slippery. These are definitely instances when you need good footing.

An international team of scientists has concluded that mining in the "Canadian Flathead" north of Glacier National Park would harm both Glacier and the adjoining Waterton Lakes National Park in Canada.

For most of us, a trip to Hawaii and its national parks is not a spur-of-the-moment adventure. But that's not to say you can't keep an eye on the Big Island's two active volcanoes from the comfort of your home.