They can be as annoying as mosquitoes, buzzing high overhead and encroaching on the national park experience for visitors on the ground. At Hawai'i Volcanoes National Park, the sounds of helicopters hauling "flight-seers" can intrude on those watching, and listening to, the eruptions within the Halemaʻumaʻu Crater of Kīlauea volcano or hiking Kīlauea Iki Trail.

More than four decades after a large swath of Big Bend National Park was identified as potential wilderness, there's a grassroots effort under way to convince Congress that now is the time to transform it into official wilderness.

Beginning On Tuesday you'll need to pay an entrance fee or show an annual pass to get into Vicksburg National Military Park in Mississippi and Louisiana.

While two river guides, armed with a UV flashlight, searched the beach for scorpions, I wandered in the other direction down the shoreline of the Colorado River to stare into the night sky at the Milky Way and its surrounding twinkling diamonds of light.