Guardian: Only from Cerro Colorado a rocky outcrop that rears vertiginously over the treetops is it possible to make out the vastness of the Gran Chaco as it stretches from this corner of Bolivia beyond the horizon into Paraguay. This enormous swath of dry forest and scrubland, where every plant or tree bears thorns, is South America's second largest wilderness after the Amazon rainforest.
The Gran Chaco is threatened on all sides: Mennonite cattle ranchers have bought up large tracts in Paraguay and...