shorelines, thickets or interrupted strips of coyote 

 willow (Salix exigua) on the banks and flats, and open 

 flats colonized by wild licorice {Glycyrrhiza lepidota) and 

 Pascopyrum smithii. There were occasional grassy banks 

 with scattered patches of prairie cordgrass {Spartina 

 pectinata) and Canada wild-rye (Elymus canadensis) , but 

 they were heavily invaded by quackgrass (Agropyron 

 repens) and smooth brome {Bromus inermis), so it was 

 not clear whether this is a discrete local vegetation 

 feature. 



OVERALL BIODIVERSITY SIGNIFICANCE: 

 The Missouri River Bottomlands RNA has significance 

 as representing a major Great Plains river valley and its 

 accompanying natural succession and geological 

 processes. It is a fitting example with three major 

 islands, an array of cottonwood stands at different 

 successional stages, bottomlands with the full suite of 

 shrubland communities, and boundaries along app. 

 nine miles that take in many of the valley slope 

 communities. 



It is contiguous with and is accessible overland via the 

 Two Calf-Douglas-fir RNA, discussed below. The 

 Douglas fir forest is not otherwise represented in 

 Missouri River Bottomlands RNA, and the two 

 together represent an outstanding example of the 

 Missouri Breaks gradient and complement one another. 

 Together they contrast with and complement the 

 drastically different vegetation of the Limber Pine 

 RNA, also in a Missouri Breaks setting over 60 miles 

 east, but with a predominantly sandstone, rather than 

 shale bedrock. 



This RNA is known to harbor the following arumals 

 species of special concern: bald eagle (HaUaeetus 

 leucocephalus) , Ferrugineous hawk (Buteo regaUs), 

 Sturgeon chub {Hybopsis geUda) , Sicklefin chub 

 {Hybopsis meeki), and a major Missouri River 

 population of pallid sturgeon (Scaphirhynchus alhus) 

 above Fort Peck. Most of these have territories that 

 extend beyond the limits of RNA boundaries. Wildlife 

 values were not evaluated. 



LAND USE: 



Extensive segments of the Missouri River bottomlands 

 were plowed, representing over half of the bottomlands 

 rurming through the center of the study area, and 

 including all accessible, large flats. These were 

 subsequently seeded to non-native species. 

 Homesteaders also based their ranching operations in 

 the valley, and prior to settlement, woodhawkers cut 

 timber to supply passing ferries. 



Most of the area has not been grazed since the late 

 1960s or the early 1970s (Haglan pers. commun.) 



Boating, motorized travel on existing roads, and 

 hunting are regular recreational activities. The site 

 adjoins James Kipp Campground and Boat Ramp, and 

 is the lower 9 mile end of the 149 mile -long Wild and 

 Scenic segment of the Missouri River. 



MANAGEMENT COMMENTS: 

 The flooding regime is modified by upstream 

 impoundments, diminishing the magnitude of floods, 

 increasing the rates of water erosion, and perhaps 

 altering the character of ice jams. The highwater 

 conditions of 1997 were reflected in overtopping 

 cutbanks and new- or newly-expanded silt and gravel 

 deposits. 



Habitats that are flooded have the continuous threat of 

 invasion by water-borne exotics like Russian knapweed 

 (Centaurea repens), one of the most invasive exotic 

 species at present in the bottomlands of the RNA. 

 Water is not its only dissemination vector, and the 

 bottomland plantings of non-native species are 

 vulnerable to its expanded invasion in general. One of 

 the most serious knapweed invasions is on Hess 

 Bottoms, located above the best-condition cottonwood 

 stands. Invasion by Tamarisk chinensis (tamarisk) is 

 another serious potential threat to riverside habitat 

 though it was not observed in the limited study area 

 visit. 



In the uplands, yellow sweetclover (Melilotus officinalis) 

 is widespread and appears to be particularly abundant 

 on shale uplands and some breakland areas that have 

 burned. 



Prairie Dog Island Research 

 Natural Area 



ENVIRONMENT: 



Prairie Dog Island is a 15 acre island in the upper end 

 of the Dry Arm, a major south-trending arm at the 

 eastern end of Fort Peck Reservoir. Its highest point 

 rises less than 60 feet above water level. This site is 

 somewhat atypical of Missouri River Breaks Subsection 

 (f) of the Northwestern Glaciated Plains Section 

 (33 ID, Nesser et al. 1997) in that it is not dissected but 

 gently rolling terrain and the predominant soil texture 

 is a fine sandy loam, indicating a weathering from 

 mainly sandstone. The climatic regime is essentially 

 Continental with hot summers and frigid winters; 35% 



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