About Denison Mines

Denison Mines Corp., through its subsidiaries, primarily engages in uranium exploration and development. The company’s uranium property interests are held directly by the company or indirectly through Denison Mines Inc. (DMI), Denison Waterbury Corp., and Denison AB Holdings Corp. Mineral Properties The company’s mineral property interests are located in the Athabasca Basin region of northern Saskatchewan, the majority of which are located in the eastern portion of the Athabasca Basin, which is host to considerable existing infrastructure, including uranium mines and mills, and provincial powerlines and highways. As of December 31, 2022, the company had direct interests in 32 mineral properties in the Athabasca Basin, consists of 210 claims covering 295,328 hectares. The company holds additional indirect interests in various uranium project joint ventures in Canada through its 50% ownership interest in JCU (Canada) Exploration Company, Ltd. (JCU). The company’s exploration and evaluation operations in Saskatchewan, including its office in Saskatoon and various project interests in northern Saskatchewan, are located in regions covered by Treaty 6, Treaty 8 and Treaty 10, which encompass the traditional lands of the Cree, Dakota, Dene, Lakota, Nakota, Saulteaux, within the homeland of the Metis and within Nuhenene. Athabasca Basin The Athabasca Basin covers an area of approximately 100,000 square kilometres in northern Saskatchewan and northeastern Alberta. The Athabasca Basin is one of the principal uranium-producing districts in the world and is host to the world’s highest-grade and some of the world’s largest uranium mines and deposits, including the McArthur River mine and Cigar Lake mine located in the eastern Athabasca Basin. Wheeler River The Wheeler River project is the largest undeveloped uranium project in the infrastructure-rich eastern portion of the Athabasca Basin region, in northern Saskatchewan. The project is host to the high-grade Phoenix and Gryphon uranium deposits, discovered by the company in 2008 and 2014, respectively, and is a joint venture between the company (90%) and JCU (10%). The company is the operator/manager of the project. The property is located along the eastern edge of the Athabasca Basin in northern Saskatchewan, Canada. The property consists of 19 mineral claims totaling 11,720 hectares. Waterbury Lake The Waterbury Lake Uranium Limited Partnership (WLULP) is held by the company (67.40%) and Korea Waterbury Uranium Limited Partnership (KWULP) (32.58%) as limited partners and Waterbury Lake Uranium Corporation (WLUC) (0.02%), as general partner. The company holds a 60% interest in WLUC (KWULP, 40%) and, in aggregate, holds a 67.41% interest in the WLULP through its limited partner and general partner ownership interests (KWULP, 32.59%). The company is operator of the project. The Waterbury Lake property is located within the eastern part of the Athabasca Basin in Northern Saskatchewan. The Waterbury Lake project, as of December 31, 2022, consists of thirteen (13) mineral dispositions, covering 40,256 ha and contains two deposits: the THT deposit and Huskie deposit. Huskie Deposit The Huskie Deposit is estimated to contain an inferred mineral resource, using a base case cut-of-grade of 0.10% U3O8, totaling 5,687,000 lbs U3O8 based on 268,000 tonnes at an average grade of 0.96% U3O8 (100% basis). McClean Lake The McClean Lake projects are owned by the company (22.5%) and Orano Canada (77.5%). Orano Canada is the operator/manager of the projects. The McClean Lake property is located within the eastern part of the Athabasca Basin in northern Saskatchewan. The mineral property consists of four (4) mineral leases covering an area of 1,147 hectares and 13 mineral claims covering an area of 3,111 hectares. The right to mine the McClean Lake deposits was acquired under these mineral leases, as renewed from time to time. Midwest The Midwest project is owned by the company (25.17%) and Orano Canada Inc. (Orano Canada) (74.83%) pursuant to the Midwest Joint Venture Agreement. Orano Canada is the operator of the project. The Midwest property is located within the eastern part of the Athabasca Basin in northern Saskatchewan. The property consists of three (3) contiguous mineral leases, covering 1,426 hectares and contains both the Midwest Main and Midwest A deposits. The mineral lease containing the Midwest Main deposit (ML 5115) is 556 hectares in size. Other Exploration Properties Crawford Lake A SML EM survey was completed on the company’s 100%-owned Crawford Lake property to better define basement conductivity associated with the F2 conductor. Ford Lake The Ford Lake project is wholly-owned and operated by the company, and consists of 9,649 hectares in five dispositions. The project is located approximately 40 kilometres southwest of the high-grade Phoenix deposit. During the first quarter of 2022, the company completed an exploration drilling program. The 2022 drilling program was highlighted by hole FD-22-10, which encountered low-grade uranium mineralization grading 0.08% eU3O8 over 0.4 metres and elevated radioactivity coincident with strong, structurally-controlled hydrothermal alteration, all indicative of a potentially mineralizing system. Johnston Lake, Candle Lake, and Darby Property-scale Z-Tipper Axis Electromagnetic (ZTEM) surveys were completed at the company’s Johnston Lake, Candle, and Darby properties during the second quarter of 2022. The ZTEM data for Johnston Lake will be integrated with the results of a Resistivity/ Magnetotelluric survey completed in 2022. Moon Lake South The Moon Lake South Property is 75%-owned, and operated, by the company, with the remaining 25% owned by CanAlaska Uranium Ltd. The property consists of one claim for 2,716 hectares. Waterfound River Waterfound is operated by Orano Canada. The company has an effective 24.68% ownership interest in the project, including its 11.78% direct interest and a 12.90% indirect interest from its 50% ownership of JCU. Wolly The Wolly project is operated by Orano Canada. The 2022 Wolly exploration program, completed in the first quarter of 2022, consisted of 10 km of EM surveying on the West Creek grid, and 2,037 metres of diamond drilling at the Geneva and Rainbow north areas. The highlight of the drill program was from drilling at the Geneva area, located in the west-central portion of the property, where drill hole GN-38 intersected a narrow vein of low-grade uranium mineralization approximately 7 metres below the unconformity, grading 0.08% eU3O8 over 0.2 metres. Operations McClean Lake Mill & Cigar Lake Toll Milling The MLJV owns a state-of-the-art uranium processing facility located on the eastern edge of the Athabasca Basin in northern Saskatchewan, approximately 750 kilometres north of Saskatoon. Orano Canada is the operator/manager of the facility. During the year ended December 31, 2022, the McClean Lake mill processed approximately 18 million pounds U3O8 for the CLJV. Mill Licence The McClean Lake site is operated under various permits, licences, leases and claims granted and renewed from time to time, all of which are in good standing. Government Regulation Environmental matters related to the McClean Lake uranium facility and the Midwest project are regulated by the Canadian Nuclear Safety Commission (CNSC) and the Saskatchewan, the Environmental Assessment Act is administered by the Ministry of Environment (SKMOE). History The company was founded in 1954. The company was incorporated in 1954. It was formerly known as International Uranium Corporation and changed its name to Denison Mines Corp. in 2006.