Lost Creek

Lost Creek ISR Mine and Processing Facility, Wyoming

Ur-Energy’s Lost Creek mine is the largest ISR uranium mine in the United States and is ramping up to full production. The same property also hosts the company’s large-scale processing facility, which acts as a hub for both the Lost Creek mine and the Shirley Basin mine.

Importantly, the Lost Creek property’s estimated 13-year mine life is based on production from just a small percentage of the vast land package. Constituting a total of 55 square miles, the project has superb near mine expansion potential.

The Company has already identified major mineralized trends to the north, west, and south of the existing mine. Of particular note, Lost Creek South is considered highly prospective and has being prioritized for future exploration drill testing.

Lost Creek Property Resource Estimate

The Lost Creek Property represents the composite of six individual contiguous Projects: Lost Creek Project, LC East Project, LC West Project, LC North Project, LC South Project and EN Project. The fully licensed and operating Lost Creek Project is considered the core project while the others are collectively referred to as the Adjoining Projects. The Adjoining Projects were acquired by the Company as exploration targets to provide resources supplemental to those recognized at the Lost Creek Project.

A Technical Report was filed for the Lost Creek Property (the “Lost Creek Report”) on March 9, 2026. The Lost Creek Report provides the most recent resource update.

The current mineral resource estimate for the property is 11.9 million pounds eU3O8 in the Measured and Indicated categories, and 10.4 million pounds eU3O8 in the Inferred category.

Learn more about Lost Creek and the Company’s full portfolio by viewing the investor presentation.

Cautionary Note Concerning Disclosure of Mineral Resources:

The Technical Report for the Lost Creek Property The Lost Creek Report on our website was prepared in accordance with both U.S. securities laws pursuant to Regulation S-K, Subpart 1300 (S-K 1300) and Canadian National Instrument 43-101, Standards of Disclosure for Mineral Projects (NI 43-101) and the Canadian Institute of Mining, Metallurgy and Petroleum Definition Standards for Mineral Resources and Mineral Reserves. NI 43-101 is a rule developed by the Canadian Securities Administrators which establishes standards for public disclosure an issuer makes of scientific and technical information concerning mineral projects. The Lost Creek Report is preliminary in nature and includes inferred mineral resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves. Mineral resources that are not mineral reserves do not have demonstrated economic viability. The estimated mineral recovery used in the Lost Creek Report is based on recovery data from wellfield operations to date at the Lost Creek Property. There can be no assurance that recovery at the estimated level will be achieved.