Date: 1988 



The Billings 1X2 sheet (1:250,000) just barely includes Half breed 

 and Hailstone (??) at it's northern margin. The maps shows outcrop 

 area and Stiff diagrams of water quality for different aquifers, 

 along with some subsurface structural information. 



Map 9F, showing data for Upper Cretaceous through Quaternary 

 aquifers, shows nothing for the Hailstone/Half breed area. 



Map 9E, showing data from Eagle sandstone through the Bearpaw 

 shale, shows the Eagle underlying both basins at depths of a few 

 hundred feet. The few nearby chemical analyses shown from the 

 Eagle and Judith River aquifers are sodic with subequal sulfate and 

 bicarbonate concentrations and TDS up to 5300. 



Map 9-D, showing the Dakota sandstone through Telegraph Creek 

 Formations, shows top of Dakota sandstone at a depth of a couple 

 of thousand feet. Chemical analyses shown indicate highly variable 

 water quality, with Frontier Fmn analyses ranging up to 26400 mg/1 

 but also down to less than 2000 mg/1. Dakota analyses similarly 

 variable. 



9-A through C provide data for older, deeper aquifers. 

 Hewitt Lake. 



Bibliographic source: Montana Bureau of Mines and Geology 

 Publications Index 



Author : Perry , E . S . 



Title: Geology and artesian water resources along Missouri and 

 Milk Rivers in northeastern Montana. 



Series: MBMG Memoir 11 



Date: 1934 



The emphasis of this outdated but interesting report is on the 

 hydrologic and hydrogeologic impacts of the Fort Peck Reservoir and 

 dam, under construction at the time. The document includes a 

 generalized geologic map at a scale of about 1:125,000 showing the 

 Hewitt Lake area underlain by undifferentiated formations "older 

 than the Judith River Formation". [Apparently Claggett Shale.] 



29 



