80 



Plate 35.— Classification: system Riverine, subsystem Upper Perennial, class Rock Bottom, subclass Rubble, water regime 

 Permanently Flooded, WATER CHEMISTRY Fresh. Many of the boulders in this river exceed 1 m (3.3 ft) in diameter. (Matanuska- 

 Susitna Borough, Alaska; June 1985; Photo by F. C. Golet) 



