The Little Knife Field, 12 by 2.5 to 4 miles (19.2 × 4 to 6.4 Km.), lies beneath a broad northward plunging anticline with less than 100 feet (30 m) of structural relief. Production is from early diagenetic porosity in the Mission Canyon Formation. The discovery well flowed 480 BOPD of 43° sour crude from 8′ (2.44 m) of perforations. Cumulative field production from February, 1977 to March, 1980 is over 10,000,000 BO.

The Mission Canyon Formation is interpreted as a regressive shoaling upward sequence. It is punctuated by carbonate cycles deposited in deeper and more open marine waters towards its base and shallower and more restricted waters towards its top. The cycles are more difficult to identify up section. The formation may be divided into six informal zones:

1. A)

   A cap of bedded and nodular anhydrite associated with both a dolomite matrix and laminated interbeds of dolomite whose interpreted depositional setting is supratidal.

2. B)

   Separated into;

   1. 1)

      an upper portion of interbedded porous, lenticular skeletal wackestones and dense wackestone/grains tones. Interpreted depositional setting of the skeletal wackestones is shallow subtidal while the wackestone/grains tones are part of an intertidal barrier.

   2. 2)

      a lower portion of dolomitized burrowed pelletal wackestone/packstones, which forms a major reservoir. Interpreted depositional setting is restricted shallow marine.

3. C)

   Dense dolomitized pelletal wackestone with crinoid columns. Depositional settingh is restricted marine to transitional marine.

4. D)

   Is the other major reservoir zone, and is partially dolomitzed porous burrowed skeletal wackestone and its depositional setting is the seaward portion of a protected shelf and transitional into open marine.

5. E)

   Dolomitized crinoidal and brachiopod mudstone/wackestone, depositional setting is restricted to transitional marine.

6. F)

   Alternating skeletal and pelletal packstones and mudstones interpreted as from the open marine.

Reservoir beds have also undergone slight to moderate anhydrite replacement of skeletal detritus, which later dissolved.