Lame Steer National Wildlife Refuge 



Climatic setting. The net annual precipitation balance for Lame 

 Steer NWR (from the MAPS database) is -23 inches, toward the less 

 evaporative end of the range shown for sample sites of the 

 unglaciated plains. Mean monthly precipitation for the Wibaux 2E 

 climatic station shows a broad summertime peak with a June maximum. 

 Annual total precipitation for the Wibaux 2E site shows an apparent 

 periodicity with a 5 to 7 year cycle shown by the 3-year running 

 average. Annual totals were below the mean for the period of 

 record during most of the 1980s. Data for the two years prior to 

 sampling were not retrieved for this site. 



Geologic setting. The Lame Steer site and the contributing drainage 

 basin are underlain by the Tongue River Member of the early 

 Tertiary Fort Union Formation, made up of sandstone, siltstone, 

 mudstone and coal. Surficial deposits are inferred to be local in 

 origin and distribution, and to reflect the lithologies composing 

 the Fort Union Formation. 



Hydrologic type. The Lame Steer wetland is an artificial 

 impoundment of an intermittent second(?) order stream. The 

 reservoir has an outlet structure and surface outflow; the 

 frequency and duration of surface outflow are unknown, however. 



Basin characteristics. The Lame Steer impoundment has one of the 

 higher catchment to wetland area ratios among sample sites of the 

 unglaciated plains. Sandstone aquifers of the Fort Union Formation 

 (and possibly clinker) are inferred to provide shallow ground-water 

 storage within the Lame Steer catchment. The water depth is 

 unknown but is inferred from the surrounding topography to be 

 probably no more than 10 feet. 



Water chemistry. At the time of sampling. Lame Steer Reservoir 

 contained moderately alkaline, "oligosaline" sodium-sulfate water. 

 Mineral equilibria indicate oversaturation with carbonate species. 

 Ammonium and nitrate concentrations were both below detection 

 limits; phosphorous concentrations (total and orthophosphate) and 

 the total organic carbon concentration also ranked toward the lower 

 end of the range shown for Great Plains sites. Arsenic, boron and 

 iron concentrations ranked relatively low in the ranges shown for 

 Great Plains sites. At slightly above the reporting limit, the 

 lead concentration ranked high among similar sites. Other trace 

 element concentrations were reported to be below reporting limits. 



Chemical history. No previous water chemistry data from this site 

 are known . 



Sediments. Arsenic, boron, copper, iron, nickel, vanadium, and 

 zinc all rank toward the middle of the ranges shown by sites of 

 this classification, while other trace element concentrations were 

 mainly below reporting limits. Of the reported concentrations, 

 only boron exceeds the mean soil concentration for the western 



