More plant and animal species grace Bolivia’s new Madidi National Park than any other preserve in South America. Yet the government plans to build a new hydroelectric dam here, which would endanger one of the last pristine tropical ecosystems in South America.

The results of my two-month assignment in Madidi can be seen in the March 2000 NATIONAL GEOGRAPHIC and in this gallery. I consider the previously unpublished images presented here evidence for the case to protect this rare and special place.