Rachel Carson, author of Silent Spring, understood nature and the value it holds for us.

Timing, as they say, is everything. Particularly in springtime, when you're waiting for the tulips to bloom, the dogwoods to flower, and the crocuses to appear. At Mammoth Cave National Park in Kentucky, officials hope you'll alert everyone when you see that first bud burst into color.

Looking for a nice, long bike ride to stretch out your legs this summer? Sign up for the 465-mile Cycle Greater Yellowstone ride.

Big Bend National Park and the Rio Grande Wild and Scenic River claim 245 miles of this renowned river. And while many of those miles wend their way through rugged and remote canyon country, sections of the river nevertheless are on the state of Texas’ list of impaired water bodies. The primary concern is high total dissolved solids (high salinity), but bacteria can be a problem in the very upper reach.