Figure 1.  The entrance to Porcupine Cave lies just above the orange talus slope in the center of the ridge. This view shows the landscape of South Park.  Photo by A.D. Barnosky, reproduced with permission from A.D. Barnosky, ed., Biodiversity Response to Climate Change in the Middle Pleistocene: The Porcupine Cave Fauna from Colorado, © 2004 by The Regents of the University of California.