Per-capita water use has declined in 100 communities that depend on the Colorado River, the primary source of freshwater to much of the southwest. But as populations expand, overall water consumption is still climbing.
Obama administration must decide by midsummer whether to extend a freeze on uranium mining claims near the Grand Canyon. A recent report cites 10 national 'treasures' at risk.
A study by the Jet Propulsion Laboratory shows that the Baja earthquake in April acted in unexpected ways. It also could set off another major quake in three to 30 years.
Politicians cannot calculate the economic profits and losses of government interventions.
Canyon formation: A single catastrophic flood capable of cutting into bedrock is extremely rare, but some gushers could form canyons very quickly.
For a geologist, the 8-mile hiking trail to the Grand Canyon's floor is an irresistible lesson in Earth's history.
10 - The Gateway Arch: Located in St. Louis, Mo., The Gateway Arch, or the Gateway to the West, is 630 ft. tall and 630 ft. wide. It was completed in 1965. Visitors can take a tram to to top for a spectacular view of the Mississippi river and southern Illinois.
The US centenarian population is doubling every decade – and they're redefining aging and longevity.
For the brave reader ready to tackle it, this sprawling text offers a fascinating glimpse of a corner of America at work.
The Amazon Rainforest is one of 28 sites picked as finalists in a global poll to name the New Seven Wonders of Nature, conducted by the Swiss nonprofit New7Wonders Foundation. The Brazilian Amazon, pictured here, harbors 40 percent of all remaining tropical rainforest, playing a vital role in global biodiversity and in protecting the earth's climate.