Longleaf pine savanna, one of the most biologically diverse ecosystems in North America, once covered millions of acres in the southeastern U. S. from Virginia to Texas, but much of it is gone because of development, fire suppression practices and timber harvesting.

The grand mountain known simply as Denali is the highest peak in North America, at 20,310-feet-elevation, capable of often creating its own weather. I spent 8 days in Alaska’s Denali country and the mountain kept its majesty to itself.

Allison Sterner hiked to the summit of Mount Monadnock in New Hampshire with me when she was 8 years old. We hiked it again this week, 32 years later, after drenching rain and found the trail slippery and a big challenge.

Geological formations like Balanced Rock in Arches National Park are enormously popular attractions in the national parks of southern Utah, amid the striking flora and fauna of the desert Southwest.

The Cahaba River in central Alabama is a delight to explore in spring when the rare Cahaba lily blooms in rocky shoals. My son and I joined the Cahaba “Riverkeeper” for a 5-mile paddle on this biological cornucopia of a river. Photo courtesy of Cahaba Riverkeeper.

On the last day of summer, a serene quiet morning paddling in a quiet tidal marsh in the lower Connecticut River in Connecticut.

North Cascades National Park in Washington State is a massive park with vast areas of wilderness, ancient forests and streams and rivers that run cold and pure.

In one sentence, Henry David Thoreau, the 19th Century Concord naturalist and philosopher, gave us an inspirational message on environmental consciousness that is still appropriate on Earth Day.

Old-growth forest is a rarity in the eastern U. S., but there’s still some left in Congaree National Park near Columbia, South Carolina. Some of the trees are truly enormous.

Watching masses of horseshoe crabs emerge from the sea to spawn on a beach, mobbed by shorebirds feeding on the freshly laid eggs, was a special glimpse into a riveting natural phenomenon.