IsoEnergy Intersects 74.0% U3O8 Over 3.5m Within 38.8% U3O8 Over 7.5m in Drill Hole LE20-76

VANCOUVER, Dec. 1, 2020 - IsoEnergy Ltd. ("IsoEnergy" or the "Company") (TSXV: ISO) (OTCQX: ISENF) is pleased to report the final chemical assay results from the summer drilling program completed in late October at the Hurricane zone. The Hurricane zone is a recent discovery of high-grade uranium mineralization on the Company's 100% owned Larocque East property (the "Property") in the Eastern Athabasca Basin of Saskatchewan.

Highlights:

• South extension drill hole LE20-76 intersected 7.5m of uranium mineralization that averages 38.8% U₃O₈, including 3.5m of off-scale radioactivity that averages 74.0% U₃O₈ (Figure 1)
• The most southerly drill hole on section 4460E, LE20-77, intersected 8.0m of uranium mineralization that averages 2.6% U₃O₈
• The three westernmost sections are open to the south
• Company is well funded with $11.8M in the treasury

Note: Off-scale radioactivity is >65,536 total gamma counts per second (CPS) from drill core measured with an RS-125 hand-held spectrometer (RS-125).

Craig Parry, Chief Executive Officer commented: "Ending the program with the best drill hole to date is a remarkable way to conclude our summer drilling program, which has demonstrated that Hurricane is a major new high-grade uranium discovery. We look forward to additional high-grade drilling in the New Year and continuing to deliver for our shareholders."

Steve Blower, Vice President of Exploration commented: "The hard work of our talented Technical team led by Andy Carmichael (Senior Geologist) and Justin Rodko (Project Geologist) resulted in a safe and very successful summer drilling program as exemplified by these final assays. Their understanding of the controls on mineralization at the Hurricane zone is the primary reason for our success. Further, our programs have benefitted from many service providers, the most important of which have been Bryson Drilling and Little Rock Enterprises (camp and expediting)."

Summer Drilling Summary

The expanded 24 drill hole summer program was focused on extending the high-grade area on the western side of the Hurricane zone. It was successful, with many of the best intersections at the zone to date being reported. These include:

• LE20-76: 7.5m @ 38.8% U₃0₈, including 3.5m @ 74.0% U₃0₈
• LE20-72: 6.0m @ 6.2% U₃0₈, including 1.5m @ 20.7% U₃0₈
• LE20-68: 11.0m @ 6.9% U₃0₈, including 1.5m @ 49.3% U₃0₈
• LE20-64: 5.0m @ 48.8% U₃0₈ including 4.0m @ 57.5% U₃0₈
• LE20-62: 4.5m @ 6.2% U₃0₈ including 2.5m @ 11.1% U₃0₈
• LE20-57: 10.0m @ 11.7% U₃0₈ including 2.5m @ 46.0% U₃0₈
• LE20-54: 9.0m @ 12.8% U₃0₈ including 4.0m @ 27.1% U₃0₈

LE20-76 Assays (Section 4435E)

Completed to infill a 17m gap in the Southern extension area on section 4435E between drill holes LE20-64 and LE20-62, drill hole LE20-76 intersected two long intervals of uranium mineralization. The first is a 6.5m long interval of weak sandstone hosted uranium mineralization from 312.5 to 319.0m that averages 0.1% U₃O₈. Beneath this horizon is a 7.5m thick interval of intense uranium mineralization that straddles the sub-Athabasca unconformity and averages 38.8% U₃O₈ from 322.5 to 330.0m. This intensely mineralized interval includes 3.5m of continuous off-scale mineralization from 324.0 to 327.5m that averages 74.0% U₃O₈. Figure 1 is a core photo of the intense mineralization. Figures 2 and 3 show the location of the drill hole in plan and section view, respectively.

Figure 1 – LE20-76 Core Photo of High-Grade Uranium Mineralization

LE20-77 Assays (Section 4460E)

Drill hole LE20-77 (Figures 2 and 4) was designed to evaluate the potential to extend mineralization south on section 4460E. It intersected 8.0m of uranium mineralization at the sub-Athabasca unconformity from 322.5 to 330.5m that averages 2.6% U₃O₈, including 1.0m @ 9.7% U₃O₈. The zone remains open for expansion to the south on this section.

Next Steps

All analytical results from the summer drilling program have now been released. Budgets and plans for 2021 activities at Larocque East are being finalized and will be announced in due course. A winter drilling program is anticipated that will begin after freeze-up in January.

The Larocque East Property and the Hurricane Zone

The 100% owned Larocque East property consists of 31 mineral claims totaling 15,878ha that are not encumbered by any royalties or other interests. 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 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 75m wide, and up to 11m 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 33.9% U₃O₈ over 8.5m in drill hole LE20-34. 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 330m in previous drilling.

Table 1 – Summer 2020 Drilling Program Results

Figure 2 – Hurricane Zone Drill Hole Location Map

Figure 3 – Vertical Cross-Section 4435E (Drill Hole LE20-76)

Figure 4 – Vertical Cross-Section 4460E (Drill Hole LE20-77)

Figure 5 – Larocque East Property Map

Qualified Person Statement

The scientific and technical information contained in this news release was prepared by Andy Carmichael, P.Geo., IsoEnergy's Senior Geologist, 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.

Neither the TSX Venture Exchange nor its Regulations Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

This news release shall not constitute an offer to sell or a solicitation of any offer to buy any securities, nor shall there be any sale of any securities in any jurisdiction in which such offer, solicitation or sale would be unlawful. The securities referenced herein have not been, nor will they be, registered under the United States Securities Act of 1933, as amended (the "U.S. Securities Act"), and such securities may not be offered or sold within the United States absent registration under the U.S. Securities Act or an applicable exemption from the registration requirements thereunder.

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.

Although the Company has attempted to identify important factors that could cause actual results to differ materially from those contained in the forward-looking information or implied by forward-looking information, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that forward-looking information and statements will prove to be accurate, as actual results and future events could differ materially from those anticipated, estimated or intended. Accordingly, readers should not place undue reliance on forward-looking statements or information. The Company undertakes no obligation to update or reissue forward-looking information as a result of new information or events except as required by applicable securities laws.

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SOURCE IsoEnergy Ltd.