The Bolivia Logistical Problem – Help Please?!

We have a problem in Bolivia, but it some ways it is a wonderful problem. Through our research to date it seems that we may have difficulty finding a route from Santa Cruz (where we must visit to see our charity Birdlife International’s partner Armonia whom we are seeking to raise money for) to Guajara-Marim at the border with Brazil. The road does not appear to run through without a massive 1000km de-tour to the West. Good for the area because it means less development with which comes human pressure, bad for us as we are already seeking to run a huge distance! The waterways provide the access to these parts normally, and that’s no good for a running challenge.

There seem to be three options, but we welcome (read we are desperate for!!) advice in this area:

1. Run as far North as possible viua Trinidad and try to cross East into Brazil
2. Run as far North as possible and take river transport to Guajara Marim, then back track on the Rurrenbaque to Riberalta road to the same latitude. This would involve a broken route but we would make no advantage from it
3. Run as far North as possible and take road transport back via Yucumo to the Rurrenbaque to Riberalta road to the same latitude. This, too, would involve a broken route but we would make no advantage from it
4. Run the route via Yucumo and Riberalta. No breaks in route but a huge extra distance covered

All are weather dependent, all pose serious challenges logistically. Answers on a postcard please?!!!!