Preamble. One of the great frustrations I've had about living here in Bolivia has been the lack of advanced notice one receives pertaining to races. It's out there, but you have to know where to look, and Google isn't much help; it's best to know somebody who knows stuff.
For the first time since moving to Bolivia, I have a calendar of races for which to train. They're all in Bolivia, but just this morning I discovered the possibility of a 100K in Argentina. That'd be a backup if the Ultra Trail Tiwanaku turns out to be a mixed Bike/Run event.