The Gas Hills Uranium Project is located in Wyoming. Azarga Uranium owns 100% of the project.
Location
The Gas Hills Project is located in the historic Gas Hills uranium district situated 45 miles east of Riverton, Wyoming. The Gas Hills Project consists of approximately 1,280 surface acres and 12,960 net mineral acres of unpatented lode mining claims, a State of Wyoming mineral lease, and private mineral leases, within a brownfield site which has experienced extensive development including mine and mill site production.
History
Between 1953 and 1988, various companies explored, developed, and produced uranium in the Gas Hills uranium district, including on lands now controlled by URZ. Three uranium mills operated in the district and two others nearby were also fed by ore mined from the Gas Hills district. Cumulative production from the district is in excess of 100 million pounds of uranium, mainly from open-pit mining, but also from underground mining.
The Gas Hills Project was owned by Strathmore Minerals Corporation from 2007 until 2013, when the company and the project was acquired by Energy Fuels Inc. URZ Energy purchased the project on October 31, 2016 and it is now 100% owned by Azarga Uranium.
Summary of Mineral Resources
In June 2017, a technical report was prepared by BRS Inc. on the Gas Hills Project titled “Amended and Restated Gas Hills Uranium Project, Mineral Resource and Exploration Target NI 43-101 Technical Report, Fremont and Natrona Counties, Wyoming, USA” with an effective date of June 9, 2017. The Gas Hills Project contains indicated uranium resources of 4.7 million pounds U3O8 (2.4 million tons at an average grade of 0.098% U3O8) and inferred uranium resources of 2.5 million pounds U3O8 (2.3 million tons at an average grade of 0.054% U3O8) at a 0.1 GT cut-off. Mineral resources that are not mineral reserves do not have demonstrated economic viability.
The uranium mineralization is contained in roll-front deposits hosted by arkosic sandstone beds of the Eocene Wind River Formation. The deposits are stratabound and occur from the surface to depths of approximately 450 feet in areas amenable to open-pit mining, and to depths in excess of 1,200 feet, which may be amenable to ISR. Based on areas of wide-spaced limited historical drilling and areas of past mine production, the Company believes that there is sufficient geological evidence to interpret that mineralization may extend from current mineral resource areas along identified trends. Based on a detailed review of previous work, the Company has outlined five high priority exploration targets within the project for follow-up including Day Loma, Day Loma/Loco-Lee, Loco-Lee, George-Ver, and Bullrush.
Details of the assumptions and parameters used with respect to the Gas Hills Report, including quality estimates and information on data verification, are available under the SEDAR profile of URZ Energy at www.sedar.com.
| Class | Cut-off | Tons (x1,000)(1) | Weighted Average Grade (% eU3O8) | Pounds eU3O8 (x1,000)(1) |
| Indicated | 0.10 GT | 2,407 | 0.098 | 4,729 |
| Inferred | 0.10 GT | 2,324 | 0.054 | 2,529 |
Subsequent to issuing the Gas Hills Report, the Company commenced detailed ISR studies on the Gas Hills Project. These studies focused on piezometric surface conditions and permeability of the Wind River formation confined aquifer, the primary host of uranium mineralization at the Company’s Gas Hills Uranium Project. The first study focused on piezometric surface conditions and demonstrated that three of the primary deposits at the Gas Hills Project, being Day Loma, George-Ver and Loco-Lee, were principally located within a confined aquifer that contains current hydrostatic head well above the minimum requirements to allow for the successful use of ISR mining techniques.
The second study focused on permeability (also referred to as hydraulic conductivity). A comprehensive review of pump test data for the Gas Hills Project and pump test data for other mining operations and planned mining operations in Wyoming proximal to the Gas Hills Project was conducted by Hydro-Engineering L.L.C (“Hydro-Engineering”). A summary of the review is presented below for each project:
| Project Name and Owner |
Hydraulic Conductivity Range (feet/day) |
Permeability Range (darcy) |
| Gas Hills; Azarga Uranium | 1.0 to 5.7 | 0.8 to 2.7 |
| Gas Hills (Peach); Cameco | 0.5 to 6.0 | 0.3 to 2.89 |
| Lost Creek; Ur-Energy | 0.27 to 2.78 | 0.13 to 1.3 |
Hydro-Engineering concluded that the hydraulic conductivity at the Gas Hills Project is comparable to hydraulic conductivity values at other ISR mining operations and planned mining operations in Wyoming proximal to the Gas Hills Project. Thus, the permeability of the mineralized Wind River formation confined aquifer at Gas Hills is suitable for ISR uranium mining.
As announced on April 6, 2020, the Company has identified additional uranium mineralization at the Gas Hills Project. The Company identified this additional uranium mineralization through the analysis of historical data procured by the Company (the “Gas Hills Data Set”). The analysis of the Gas Hills Data Set identified 147 mineralized drill holes with 173 intercepts equal to or exceeding a 0.2 grade-thickness cutoff using a 0.02% grade cutoff with an average U308 grade of 0.137% and an average thickness of 5.3 feet and expanded the envelope of uranium mineralization indicating the potential to supplement the existing Gas Hills Project resource estimate. Further, the analysis confirms that the uranium mineralization occurs in sandstone-hosted roll fronts located below the water table, indicating the potential for ISR amenability. The analysis of the Gas Hills Data Set has not yet been completed and as the Company continues its review, it is expected that further uranium mineralization will be identified at the Gas Hills Project.
The Gas Hills Data Set includes historical drilling information that has been reviewed by the Company’s geological team. The Company’s review of the records and information within the Gas Hills Data Set reasonably substantiate the validity of this information; however, the Company cannot directly verify the accuracy of the historical data, including the procedures used for sample collection and analysis. Therefore, the Company encourages investors to exercise appropriate caution when evaluating these results.
What’s Next
The favorable report on permeability coupled with the favorable piezometric surface conditions confirms that these two important hydrologic parameters are suitable for ISR uranium mining. The Company will continue to evaluate future ISR development options at the Gas Hills Project.
Qualified Person
John Mays, P.E. and Chief Operating Officer for Azarga Uranium is a Qualified Person under NI 43-101 – Standards of Disclosure for Mineral Projects and is responsible for and has approved the technical disclosure on this website.