Cultivating faith on the Chaco: enduring decades of hardship, Mennonite immigrants built communities that today prosper in this desolate region of Paraguay.

At dusk, the sun is a blazing red ball beyond the flat, shimmering horizon. Like muffled church bells calling worshipers to prayer, the clickety-clank of empty, metal milk vats being unloaded reverberates in the oppressive evening air peculiar to the Chaco desert. Calmly and quietly, within five minutes, farmers begin to arrive from all directions to deliver the day's produce.

There's sunburnt Fred Reimer, his characteristic straight-faced, sedulous self, lugging his cans on a beat-up tractor. Next comes beaming John Simons, stylish in Ns Michael Jordan cap, happy to josh in perfect English about the homesickness he felt for the ...