Foundation for the Advancement of Mesoamerican Studies
Famsi: Classic Maya Borders and Frontiers (2003)
A look at the geology and topography of El Paraiso valley and its influence on communication, passage and trade. Report also considers architecture and "Mayanization" of area.
Other
Virtual Sun: Maya Environment
This site from the Virtual Sun gives a detailed account of the geographical region once inhabited by the Maya People. It describes the landscape, climate, and altitude.