LOVER YELLOVSTONE RUH^ DRAINAGE 



Boundaries: Bighorn River to North Dakota border 



Drainage size: 69,103 square miles 



Main stem length: 270 miles 



Tributaries: Powder, Tongue 



Cities/Towns: Forsyth, Miles City, Glendive, Sidney, Richland 



Access: Interstate 90 



French explorers called it the Roche Jaune, meaning "yellow 

 rock," and Captain Clark in 1805 wrote, " The clifts on the South 

 Side of the Rochejhone are generally comp. of a yellowish Gritty 

 soft rock." The final stretch of the Yellowstone River, a wide, 

 tree-lined river meandering northeast to meet the Missouri in 

 North Dakota, begins at the Bighorn River, 50 miles northeast of 

 Billings (Figure 13). By this time, its transformation from a 

 mountain stream into a mighty plains river is complete. Its total 

 678 mile journey, 550 which are in Montana, is the longest free- 

 flowing river in the lower 48 states. 



Although the continental ice sheet dammed a portion of the 

 lower Yellowstone, most of the river and its tributaries can be 

 described as unglaciated plains, a country of plateaus, wind- 

 carved sandstone "hoodoos," and eroded gumbo badlands. Landforms 

 are more subdued than in the mountainous areas to the west. 

 Elevations range from about 1,880 feet where the Yellowstone 

 enters North Dakota, to roughly 4,000 feet in the mountain ranges 

 of the Big and Little Sheep Mountains. 



The lower Yellowstone is a country of prairie streams and 

 rivers where dry sage and grass uplands contrast with the cool, 

 green woody growth of majestic cottonwoods and shrubby river 

 bottoms. Woody draws dissect the land and combine to form larger 

 and larger streams until they unite into creeks such as the 

 Mizpah, Pumpkin, Rosebud, Porcupine, or Sunday. Entering Montana 

 from higher mountains in Wyoming, the Powder and Tongue rivers 

 meander along wide river valleys contributing substantial 

 quantities of water as well as sediment to the mighty Yellowstone. 

 This change of character naturally affects the river's fisheries, 

 wildlife and recreational use. 



Fisheries 



The Yellowstone River and its fishery changes character from a 

 mountain trout stream in its upper 100 miles to a warm-water 

 prairie river as it leaves the state. Above Tower Junction in 

 Yellowstone National Park, one fish species is present, the 

 Yellowstone cutthroat trout. Introduction of exotic trout 

 species, in addition to native whitefish and forage fish, brings 

 the species list to 11 in the reach upstream of the Boulder River. 



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