In the Americas with David Yetman - Season 3 (2014)

The mighty Sierra Nevada is our most important mountain range. It influences much of California's weather and produces most if its water. It was once the greatest barrier to transcontinental transportation and communication. It is a symbol of earthquakes, which created it. Tectonic geologist Eldridge Moores helps host David Yetman decipher the mysteries of the range's origins and describes the sierras' importance.

Long stretches of Brazil's northeast coast are lined with sand dunes, some of them the size of small mountains, some of them so vast that they create their own climate. Their color, shape, and composition and their relationship with wind provide a striking variety of landscapes, each with its own ecological character, its own plants and animals. The sands are also home to the cashew tree, famous for fruit and nut. One tree in particular has become a major tourist attraction.

It's the world's largest lake, vast enough to create its own climate. Lake Superior separates the U.S. and Canada, on the east by a portage canal. For a thousand years the lake has seen vibrant cultures and trade in copper. Canadian shores harbor unending forests and some of the coldest towns in the Americas. Within its waters is Isle Royale National Park.

For two hundred years Nicaragua suffered from the double insult of shaking earth-earthquakes and volcanic eruptions-and military and political interventions from the north. Today a democratic Nicaragua is promoting its diversity of cultures, its Spanish colonial heritage, and its natural wonders. Misquito Indians from the Caribbean coast and descendants of Aztecs, who hardly know each other, still flourish within the country. Nicaragua's lakes, forests, and volcanoes are finally earning the accolades they deserve.

The Brazilian state of Pernambuco, about the size of Maine, is home to the megapolis of Recife, Brazil's fifth largest city and home to more than 5 million Pernambucans. Recife's carnival, along with celebrations in its colonial suburb Olinda and the in the cities of Bezerros and Nazarene da Mata, though not as internationally famous as those of Rio de Janeiro and Salvador, are part of a flamboyant, joyous, boisterous week of immense parades, intense dances, and elaborate costumes. And invitations are not required. You can jump in at any time.

Five hundred years ago Franciscan priests journeyed to the remote city of Cuetzalan in Puebla State. The region was fertile for evangelizing, an urban area of Aztecs and Totonacans who supported a vibrant culture. Although less remote now, the traditions and languages continue in a town that venerates its fiestas and the ancient rituals they perpetuate, especially the acrobatic, airborne voladores.

Two of Alaska's vast national parks, Lake Clark and Katmai, have endured a heritage of volcanic explosions. Lake Clark is a wilderness of endless forests, lakes, marshes, glaciers, and recently active volcanoes, while nearby Katmai, born of one of history's most violent explosions, shows the aftermath of a cataclysmic eruption a century ago and how the rainforests and inhabitants have recovered. Both parks are home to abundant wildlife, while villages of native Americans continue as well, along with their traditions.