Montana

The Alberta Basin Bakken
Also refered to the Exshaw Formation is Mississippian in age and consists of black shale, siltstone and limestone and is time equivalent to the lower and middle members of the Bakken Shale. The Exshaw Formation, when present, overlies the Upper Devonian Three Forks Formation and is at the base of the Mississippian age Madison Group.

Cut Bank Sand Formation
The Cut Bank Sand formation is an oil and natural gas resource located in Montana, spanning across Pondera and Glacier Counties. There are two sands identified within the Cut Bank horizon. The upper sand ranges in thickness from 0 to 38 feet. The oil bearing lower sand varies in thickness from 0 to 52 feet. The reservoir consists of relatively clean, porous, heterogeneous sand with little to no clays present.

The Two Medicine Cut Bank Sand Unit - Cut Bank, Montana
The Two Medicine Cut Bank Sand Unit (TMCBSU) represents a southwest extension of the larger Cut Bank field. The TMCBSU was originally drilled in 1959 and has since experienced three periods of development drilling continuing through the present.

In October of 2008, a subsidiary of Arkanova Energy acquired Provident Energy Associates of Montana. Provident Energy operates the approximate 9,900 acre TMCBSU.
The company currently produces oil out of the Lower Cut Bank sand with 34 active producers and more well bores set for reactivation and recompletion.  Schlumberger estimated a remaining 20-21 MMSTB OIP (milllion stock tank barrels of oil in place).