40 C.F.R. § 147.2554
In accordance with §§ 144.7(b) and 146.4 of this chapter, those portions of aquifers currently being used for injection in connection with Class II (oil and gas) injection operations on the Wind River Reservation, which are described below, are hereby exempted for the purpose of Class II injection activity. This exemption applies only to the aquifers tabulated below, and includes those portions of the aquifers defined on the surface by an outer boundary of those quarter-quarter sections dissected by a line drawn parallel to, but one-quarter mile outside, the field boundary, and is restricted to extend no further than one-quarter mile outside the Reservation boundary. Maps showing the exact boundaries of the field may be consulted at the EPA's Region 8 Office, and at the EPA Headquarters in Washington, DC.
Areas To Be Exempted for the Purpose of Class II Injection on the Wind River Reservation
| Formation | Approximate depth | Location |
| Steamboat Butte Field | ||
| Phosphoria | 6,500-7,100 | T3N, R1W-W/2 Sec. 4, Sec. 5, E/2 Sec. 6, NE/4 Sec. 8, W/2 Sec. 9. T4N, R1W-W/2 Sec. 29, E/2 Sec. 30, E/2 Sec. 31, Sec. 32. |
| Tensleep | 6,900-7,500 | T3N, R1W-W/2 Sec. 4, Sec. 5, E/2 Sec. 6, NE/4 Sec. 8, W/2 Sec. 9. T4N, R1W-W/2 Sec. 29, E/2 Sec. 30, E/2 Sec. 31, Sec. 32. |
| Winkleman Dome Field | ||
| Tensleep | 2,800-3,300 | T2N, R1W-SW/4 Sec. 17, Sections 18, 19, 20, 29, NE/4 Sec. 30. T2N, R2W-E/2 Sec. 13, NE/4 Sec. 24. |
| Phosphoria | 2,800-3,600 | T2N, R1W-SW/4 Sec. 17, Sections 18, 19, 20, 29, NE/4 Sec. 30. T2N, R2W-E/2 Sec. 13, NE/4 Sec. 24. |
| Nugget | 1,100-1,500 | T2N, R1W-SW/4 Sec. 17, Sections 18, 19, 20, 29, NE/4 Sec. 30. T2N, R2W-E/2 Sec. 13, NE/4 Sec. 24. |
| Lander Field | ||
| Phosphoria | 1,100-3,800 | T2S, R1E-Sections 12 and 13, E/2 Sec. 24, NE/4 Sec. 25. T2S, R2E-W/2 Sec. 18, W/2 Sec. 19, Sec. 30. T33N, R99W-Sec. 4. |
| NW Sheldon Field | ||
| Crow Mountain and Cloverly | 3,400-3,600 | T6N, R3W-SE/4 Sec. 35, SW/4 Sec. 36. T5N, R3W-N/2 Sec. 1. |
| Circle Ridge Field | ||
| Tensleep | 1,500-1,800 | T6N, R2W-Sec. 6, N/2 Sec. 7. T7N, R3W-SE/4 Sec. 36. T7N, R2W-SW/4 Sec. 31. T6N, R3W-E/2 Sec. 1. |
| Phosphoria | 800-1,800 | T7N, R3W-S/2 Sec. 36. T6N, R3W-NE/4 Sec. 1. |
| Amsden | 700-l,200 | T6N, R3W-Sec. 6. |
| Rolff Lake Field | ||
| Crow Mountain | 3,500-3,700 | T6N, R3W-SW/4 Sec. 26, NW/4 Sec. 27. |
40 C.F.R. §147.2554