Located in the heart of South America, the Chaco bridges more than 100,000 square miles between the world's largest wetland, the Pantanal, the semi-tropical forests of eastern Paraguay, the grassy Argentine Pampa and the towering Andes mountains. The Chaco's eastern side, bordered by the Paraguay River, is humid and laced with small rivers, tidal grasslands and palm trees. The forests are studded with hardy trees such as the commercially valuable quebracho colorado (breakaxe) and the palo boracho (drunk wood). In the central Chaco, rain is less frequent and the vegetation ranges from hardwood forests to prohibitively thorny brushland, interspersed by meadows and lakes that range from salty to brackish. Here, the Palo Boracho takes on its characteristically drunken appearance as its thorny trunk expands like a baloon to store water. Further west, the Chaco lies in the rain shadow of the Andes mountains. Water is very scarce and low-lying sand dunes, held together by a matrix of vines, stretch for hundreds of miles.

Mennonite settlers, pacifist Christians of German descent, left Canada in the 1920s to inhabit this desolate region--the first non-indigenous people to settle here. Others, among them, Ratzlaff's parents, came from Europe fleeing persecution from communist Russia, eventually populating the central Chaco region with some 13,000 settlers. The Mennonites, desperate to find a country that would take them in, came at the invitation of the Paraguayan government, which was eager to populate the country's western fringe because of a border dispute with Bolivia.

Although the Mennonites thought they had reached the promised land, they eventually dubbed the Chaco the "Green Hell." The scissor-sharp brushland forced ranchers on horseback to wear three layers of clothes for protection, despite temperatures of 110 degrees F. The lakes and riversides bred mosquitos, poisonous snakes and cayman. In the woods lurked carnivorous pumas and jaguars. Temperatures fluctuated as much as 80 degrees from one day to the next. When they cleared the land for agriculture, the settlers often caused the area's low-lying salt water to mix with surface rainwater, turning the land into useless desert.

These harsh conditions made the Chaco the preferred place for Paraguayan dictators to send their most vocal critics into exile. To this day, few Paraguayans venture here--even for a day. Although the Chaco takes up 60 percent of Paraguay, it is inhabited only by 2.5 percent of the country's population--about 100,000 people. Indeed, when the Mennonites first arrived in the Central Chaco, they found only about 500 native people living there.

But the Paraguayan's Green Hell is a heaven for wildlife. More than 100 species of mammals inhabit the area, such as tapirs, three species of the prehistoric-looking peccary--including the endangered tagua--pumas, anteaters, jaguars and the huge South American rodent known as capybara. Nine species of armadillos--including the rare giant armadillo also live there. The Chaco's wetlands have attracted more than 400 bird species, including seven found nowhere else in the world, such as the brushland tinamou, the quebracho crested-tinamou and the spot-winged falconet. The ostrich-like ñandu also calls the Chaco home. Pink flamingos, finding snails and insects plentiful, feed in the Central Chaco's shallow salt lakes. Many reptiles also live here, such as the alligator-like cayman, and rattlesnakes.

"There is a joke that says the animals complained to God that every place they went, people would occupy, forcing them to leave," says Ratzlaff. "God said to them, I have one place where no human being will survive, so go there and you will live in peace, and that was the Chaco...and then came the Mennonites."