In the America's with David Yetman

Carnival or Mardi Gras is a time of parades and exuberant partying just before the forty days of Lent, when many Christians must adopt of more austere way of life. Latin America features hundreds of variations on the festivities. Mexico has two sensational parades like no others, in towns that are otherwise obscure--Huejotzingo in the state of Puebla and Tlacayapan in the state of Morelos.

Brazil is home to a host of venomous critters, mostly scorpions, spiders, and snakes. Each year many tens of thousands of Brazilians are stung or bitten and require treatment. Many owe their lives to antivenin produced by the Butantan Institute in São Paulo. It’s home to hundreds of thousands of venomous creatures, all contributing to the protection of human lives.

Only a few decades ago, Baja California was mostly unknown to the outside world. But crowds and developers have discovered this area and arrived in droves, threatening the very features that make the peninsula such an unusual place. Meanwhile, overharvesting in the Gulf of California has caused fish stocks to plummet and threatened the entire ecosystem.

The abundance of reptiles, especially snakes, in the Amazonian jungle is hardly surprising. Native cultures, far from fearing snakes, view them as spiritually significant elements of nature. From the gigantic anaconda to tiny tree vipers, snakes are part of life—and religion--in Brazil’s Amazon.

It’s our largest national park—larger than New England--and one-third of it is ice. One glacier is 137 miles long. The park contains active volcanoes. Its rivers of icemelt are home to salmon runs that have supported native peoples for thousands of years. Yet the glaciers are melting, and forests are drying. The park has become an enormously important natural laboratory.

Forty million people rely on water released from Lake Mead, on the Colorado River not far from booming Las Vegas, a world leader in water conservation. Far downstream huge canals de-water the river, as farmers look to technology to maintain their productivity; Californians deliver water to their vast population and land; and Mexico receives its entitlement.

Phantom Ranch, accessible only by trail, is the Grand Canyon's sole permanent settlement. From there west, the canyon narrows and darkens as the Colorado River carves its way throughthe oldest rock in the Southwest. From the north and south sides, canyons “slots” reach the churning river. Finally, the tamed river meets the placid waters beyond.

Boating through the Grand Canyon with a group of water experts provides a setting for reflection on the Colorado River—its power, its accomplishments, and its vulnerabilities. We put in at Lee’s Ferry and immediately are introduced to rapids and the evolution of the world’s greatest geological spectacle.