IsoEnergy Expands Hurricane Zone North and South

SASKATOON, Sept. 21, 2021 - IsoEnergy Ltd. ("IsoEnergy" or the "Company") (TSXV: ISO) (OTCQX: ISENF) is pleased to announce initial scintillometer results from summer drilling at the Hurricane zone. Hurricane was discovered in July 2018 and is a high-grade uranium mineralization located on the Company's 100% owned Larocque East property (the "Property") in the Eastern Athabasca Basin of Saskatchewan.

Tim Gabruch, President and Chief Executive Officer commented: "The team has successfully transitioned our summer drilling program from Geiger to Larocque East. The objective of this program is to expand the known area of mineralization at Hurricane and in parallel explore for additional zones of mineralization to the east. These early results at Hurricane are very positive in terms of expanding the Hurricane zone, with subsequent drilling to incorporate further step outs to the north, south and east."

Andy Carmichael, Vice President of Exploration commented: "Drilling at Larocque East continues to grow the Hurricane zone. LE21-78C1, our first drill hole of the program, intersected the broadest intersection of radioactivity to date at Hurricane and subsequent drill holes have expanded the zone to the north and south. We are encouraged by these early expansion drilling results and are looking forward to further testing the extent of mineralization at Hurricane."

Note: Radioactivity is total gamma counts per second (CPS) from drill core measured with an RS-125 hand-held spectrometer (RS-125).

LE21-78C1 (Section 4460E)

Drill hole LE21-78C1 was completed on section with and 8m south of previously reported drill hole LE20-77 (8.0m averaging 2.6% U₃O₈). LE21-78C1 intersected 12.0m of uranium mineralization (>500 CPS) from 248.5 to 260.5m, including 2.0m of strong mineralization (>30,000 CPS) from 257.5m to 259.5m. The mineralization in LE21-78C1 has expanded the Hurricane zone 8m to the south on section 4460E. LE21-78C1 also intersected elevated radioactivity in the basement associated with significant structure and alteration, suggesting further potential for southern expansion on this section. Figures 2 and 3 show the location of the drill hole in plan and section view, respectively.

LE21-80 (Section 4435E)

Drill hole LE21-80 was completed to test for a north-easterly extension of very strong mineralization intersected by previously reported drill hole LE20-34 (33.9% U₃O₈ over 8.5m). LE21-80 reached the unconformity 19m east-northeast of LE20-34 and intersected 3.5m of uranium mineralization (>500 CPS) from 326.0m to 329.5m, including 2.0m >5,000 CPS from 326.0 to 328.0m. Figures 2 and 4 show the drill hole in plan and section view, respectively.

LE21-82 (Section 4485E)

Drill hole LE21-82 was completed on section with and 26m south of previously reported drill hole LE20-71 (2.0m averaging 2.4% U₃O₈). LE21-82 intersected 4.5m of uranium mineralization (>500 CPS) from 328.5 to 333.0m, including 1.0m >5,000 CPS from 331.0 to 332.0m. The mineralization in LE21-82 has expanded the Hurricane zone 26m south and the mineralized footprint is now at least 94 metres in width on Section 4485E. Figures 2 and 5 show the drill hole in plan and section view, respectively.

LE21-84 (Section 4435E)

Drill hole LE21-84 was completed on section with and 28m north of previously reported drill hole LE20-67 (0.2% U₃O₈ over 2.0 metres). LE21-84 intersected 3.0m of uranium mineralization (>500 CPS) from 326.5m to 329.5m, including 0.5m >5,000 CPS. The mineralization in LE21-84 expanded the Hurricane zone 28 metres to the north and the mineralized footprint is now at least 93 metres in width on section 4435E. Figures 2 and 4 show the drill hole in plan and section view, respectively.

The Larocque East Property and the Hurricane Zone

The 100% owned Larocque East property consists of 33 mineral claims totaling 16,780ha. Two of the project's claims distal to the Hurricane zone are subject to a 2% Net Smelter Returns Royalty of which 1% may be bought back for $1Million at IsoEnergy's discretion. Larocque East is immediately adjacent to the north end of IsoEnergy's Geiger property and is 35km northwest of Orano Canada's McClean Lake uranium mine and mill.

Along with other target areas, the Larocque East Property covers a 15-kilometre-long northeast extension of the Larocque Lake conductor system; a trend of graphitic metasedimentary basement rocks that is associated with significant uranium mineralization at the Hurricane zone, and in several occurrences on Cameco Corp. and Orano Canada Inc.'s neighbouring property to the southwest of Larocque East. The Hurricane zone was discovered in July 2018 and was followed up with 29 drill holes in 2019 and an additional 48 drill holes in 2020. Dimensions are currently 575m along-strike, up to 94m wide, and up to 12m thick. The zone is open for expansion along-strike to the east and to the north and south on some sections. Mineralization is polymetallic and commonly straddles the sub-Athabasca unconformity 320 m below surface. The best intersection to date is 38.8% U₃O₈ over 7.5m in drill hole LE20-76. Drilling at Cameco Corp.'s Larocque Lake zone on the neighbouring property to the southwest has returned historical intersections of up to 29.9% U₃O₈ over 7.0m in drill hole Q22-040. Like the nearby Geiger property, Larocque East is located adjacent to the Wollaston-Mudjatik transition zone - a major crustal suture related to most of the uranium deposits in the eastern Athabasca Basin. Importantly, the sandstone cover on the Property is thin, ranging between 140m and 450m in previous drilling.

Table 1 - Summer 2021 Drilling Program Results to Date

Qualified Person Statement

The scientific and technical information contained in this news release was prepared by Andy Carmichael, P.Geo., IsoEnergy's Vice President, Exploration, who is a "Qualified Person" (as defined in NI 43-101 - Standards of Disclosure for Mineral Projects). Mr. Carmichael has verified the data disclosed. All radioactivity measurements reported herein are total gamma from an RS-125 hand-held spectrometer. As mineralized drill holes at the Hurricane zone are oriented very steeply (-70 to -90 degrees) into a zone of mineralization that is interpreted to be horizontal, the true thickness of the intersections is expected to be greater than or equal to 90% of the core lengths. This news release refers to properties other than those in which the Company has an interest. Mineralization on those other properties is not necessarily indicative of mineralization on the Company's properties. All chemical analyses are completed for the Company by SRC Geoanalytical Laboratories in Saskatoon, SK. For additional information regarding the Company's Larocque East Project, including its quality assurance and quality control procedures, please see the Technical Report dated effective May 15, 2019, on the Company's profile at www.sedar.com.

About IsoEnergy

IsoEnergy is a well-funded uranium exploration and development company with a portfolio of prospective projects in the eastern Athabasca Basin in Saskatchewan, Canada. The Company recently discovered the high-grade Hurricane Zone of uranium mineralization on its 100% owned Larocque East property in the Eastern Athabasca Basin. IsoEnergy is led by a Board and Management team with a track record of success in uranium exploration, development, and operations. The Company was founded and is supported by the team at its major shareholder, NexGen Energy Ltd.

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Forward-Looking Information

The information contained herein contains "forward-looking statements" within the meaning of the United States Private Securities Litigation Reform Act of 1995 and "forward-looking information" within the meaning of applicable Canadian securities legislation. "Forward-looking information" includes, but is not limited to, statements with respect to the activities, events or developments that the Company expects or anticipates will or may occur in the future, including, without limitation, planned exploration activities. Generally, but not always, forward-looking information and statements can be identified by the use of words such as "plans", "expects", "is expected", "budget", "scheduled", "estimates", "forecasts", "intends", "anticipates", or "believes" or the negative connotation thereof or variations of such words and phrases or state that certain actions, events or results "may", "could", "would", "might" or "will be taken", "occur" or "be achieved" or the negative connotation thereof.

Such forward-looking information and statements are based on numerous assumptions, including among others, that the results of planned exploration activities are as anticipated, the price of uranium, the anticipated cost of planned exploration activities, that general business and economic conditions will not change in a material adverse manner, that financing will be available if and when needed and on reasonable terms, that third party contractors, equipment and supplies and governmental and other approvals required to conduct the Company's planned exploration activities will be available on reasonable terms and in a timely manner. Although the assumptions made by the Company in providing forward-looking information or making forward-looking statements are considered reasonable by management at the time, there can be no assurance that such assumptions will prove to be accurate.

Forward-looking information and statements also involve known and unknown risks and uncertainties and other factors, which may cause actual events or results in future periods to differ materially from any projections of future events or results expressed or implied by such forward-looking information or statements, including, among others: negative operating cash flow and dependence on third party financing, uncertainty of additional financing, no known mineral reserves or resources, the limited operating history of the Company, the influence of a large shareholder, alternative sources of energy and uranium prices, aboriginal title and consultation issues, reliance on key management and other personnel, actual results of exploration activities being different than anticipated, changes in exploration programs based upon results, availability of third party contractors, availability of equipment and supplies, failure of equipment to operate as anticipated; accidents, effects of weather and other natural phenomena and other risks associated with the mineral exploration industry, environmental risks, changes in laws and regulations, community relations and delays in obtaining governmental or other approvals.

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SOURCE IsoEnergy Ltd.