96 



Plate 51.-Classification: SYSTEM Palustrine, CLASS Unconsolidated Bottom, subclass Mud, water regime Permanently Flooded, 

 WATER chemistry Fresh-Circumneutral, SPECIAL modifier Impounded. This beaver pond is situated in the San Juan Moun- 

 tains. (Gunnison County, Colorado; Photo by R. M. Hopper) 



