Within the Sheep Mountain Project area, uranium mineralization is contained in the lower to middle Eocene Battle Spring Formation. The Battle Spring Formation, consisting of upper and lower members (designated the "A" for the lower and "B" for the upper), is a fluvial deposit. Mineralization is hosted by the Battle Spring Formation and has been described extensively since the 1960s and has been termed a "Wyoming Roll Front System." These deposits are often organic-rich, fine grained lenses in tabular, or "roll front," configurations. The uranium mineralization occurs primarily in the lower member of the Battle Spring Formation (Stephens,1964).

The host of uranium mineralization for the Project is the Battle Spring Formation. Most of the mineralization in the Crooks Gap district occurs in roll-front deposits(Bendix, 1982). Roll fronts have an erratic linear distribution but are usually concordant with the bedding. Deposits have been discovered from the surface down to a depth of 1,500 feet (Stephens, 1964). The two major uranium minerals are uranophane and autunite. Exploration drilling indicates that the deeper roll-type deposits are concentrated in synclinal troughs in the lower Battle Spring Formation. Three possible sources for uranium have been suggested: post-Eocene tuffaceous sediments, leached Battle Spring arkoses, and Precambrian granites (Granite Mountains).

Structural controls of uranium occurrences along roll fronts include carbonaceous silts ........

The Sheep Underground mine has operated as a conventional underground mine on three separate occasions. No reports of adverse ground conditions, flooding, cave-ins or any other unusual mining conditions are known to EFR. The historic mining method was a modified room and pillar method using conventional techniques. Jacklegs were used to drill out the rounds and underground track haulage was used to transport the mined material to Shaft No. 1.

The mining method proposed going forward is also a conventional method using a modified room and pillar method but utilizing modern mining equipment such as jumbo drills and scoop trams for haulage. A new double entry decline will be constructed starting at the Paydirt Pit and ending below the deposit. Haulage from the mine will be accomplished via a 36-inch conveyor within one of the double declines. The existing shafts will be used for ventilation purposes only, with exhaust fans mounted at both locations. If the existing borehole ventilation shafts can be rehabilitated, they will be used as intake shafts. The deposit is comprised of 16mineralized zones with a total thickness of approximately 350 feet. The deposit will be mined primarily from bottom to top.

Sheep Underground mining method summary:
- Development drifts will utilize dual openings. 10 by 15-foot openings will be used for haulage, and 8 by 10-foot openings will be used for transportation and ventilation.
- Mining panels will utilize multi ........

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