Table 1 Continued. 



optimum, while the poorest was 27.7 percent at Station 3 on Glendive Creek. 

 The upper reaches of Glendive Creek show qood bank cover, stability and very 

 little ungulate use resulting in a high rating. However, the lower reaches 

 of the creek have been altered and the habitat condition rating of 27.7 

 percent of optimum reflects the stream stability. Box Elder Creek rated 

 good as did Krug Creek, while Cotton Creek and a tributary to Griffith 

 Creek rated fair. 



Hydrophytes 



Aquatic plants are an important source of food for waterfowl, muskrats 

 and herbivorous fish and insects, forming the food chain base for game fish 

 and water birds. Cover for fish and aquatic invertebrates is also provided 

 by hydrophytes. A list of hydrophytes found in the Beaver Creek and 

 Yellowstone tributary streams is presented in Table 

 hydrophytes in the study area tend to be widespread 

 This is indicative of a wide ecological tolerance, 

 other four geographical affinities for the United States constitute approximately 

 15 percent of this list. Most of the species have in common a tolerance of 

 fluctuating water levels, more specifically, a tolerance to low water. As 

 the margins of the creeks gradually recede, the emergent zone has produced 

 a luxuriant growth of grasses, sedges and rushes, literally, a sedge meadow 

 or fen. Representatives of both lotic and lentic waters were identified in 

 compliance with the diversity of the creek habitats. In lieu of the limited 

 soil types in the study drainages, the overall plant community is surprisingly 

 diverse. 



4. The species of 



in geographic affinities. 



Representatives of the 



AQUATIC INVERTEBRATES 



A list of the aquatic invertebrates found in the Beaver Creek and 

 Yellowstone drainages is shown in Table 5; and their approximate distribution 

 throughout Beaver Creek and the Yellowstone River tributaries is presented 

 in Figures 10 and 11. These do not represent a complete distributional list. 

 They do, however indicate predominate forms. 



4 



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