The  majority of the Alberto Manual Brenes Biological Reserve is drained by the Rio Jamaical drainage basin, which is not easily accessed.  The river has a much more tropical, Carribean look too it, and a portion of it drains some relatively new volcanic rock, making it less safe to drink than water from Rio San Lorencito.  We drank from the small, headwater tributaries near-by.  It is a larger river than the Lorencito, and has a much wider bed, so it’s open to much more light.  Although I didn’t notice any fish, the river wasn’t devoid of life; there were tadpoles (although it may be interesting to see if the species and abundance of tadpoles compared between the San Lorencito and Jamaical) and plenty of anoles and frogs at the river’s edge potentially picking off emerging aquatic invertebrates. 

After a long hike to get the this river, a refreshing swim was incredibly welcome.