Vancouver, British Columbia--(Newsfile Corp. - August 20, 2026) - Myriad Uranium Corp. (CSE: M) (OTCQB: MYRUF) (FSE: C3Q) ("Myriad" or the "Company") is pleased to announce preliminary gamma probe equivalent uranium results from drilling at Lucky Cliff, Copper Mountain (see Figure 1). These estimates are not chemical assays and remain subject to laboratory verification.

Highlights

• Myriad's current Phase II drill program is designed to achieve two primary objectives:

  1. Verify mineralization that underpins a historical resource estimate¹ of 26.63 Mlbs eU₃O₈ and generate modern data to support a future maiden mineral resource estimate.

  2. Evaluate exploration upside by testing historical targets identified through drilling in the 1970s and assessing new targets generated by Myriad's own exploration work, that could deliver an exploration target² of between 245 and 655 Mlbs eU₃O₈.

• Myriad has now completed four drill holes at Lucky Cliff for a total of 716.6 metres (2,351 feet) of drilling.

• All four holes intersected numerous broad intervals of near-surface uranium mineralization.

• Across the four holes, 50 mineralized intervals exceed 100 ppm eU₃O₈.

• The longest mineralized interval is 19.96 metres (65.49 feet) at 269 ppm eU₃O₈ from 18 m.

• The highest grade intercepted is 1,336 ppm eU₃O₈.

• Because Lucky Cliff lies outside any area with a historical resource or endowment estimate, any mineral resource that may in future be defined there would be new and incremental to the Copper Mountain Uranium Project mineral endowment, if supported by sufficient exploration and estimation work.

Best Intervals Above 100 ppm eU₃O₈ Threshold

• ¹ GT (m%) = grade-thickness product (interval length in metres multiplied by grade in %), a standard metric for comparing the relative scale of mineralized intercepts.
• Equivalent uranium (eU₃O₈) grades are radiometric estimates derived from downhole gamma logging and are not chemical assays. They are preliminary, may be affected by disequilibrium, borehole diameter, casing, water, probe calibration and other borehole conditions, and will be verified by laboratory assay results. Verification will include standard QAQC protocols such as the insertion of blanks, standards (Certified Reference Materials) and duplicates as well as the implementation of chain of custody procedures.
• The intervals above are selected preliminary radiometric intervals reported above a 100 ppm eU₃O₈ threshold and are intended to highlight the most material intercepts by length, grade and grade-thickness. They should be read together with Appendix 1, which provides the full interval summaries at the stated reporting thresholds.
• Reported intervals are downhole lengths and do not represent true widths, which have not yet been determined.

Myriad's CEO, Thomas Lamb, commented: "These are encouraging preliminary radiometric results from a new area in the north of our recently expanded Copper Mountain Project Area and outside historical estimate boundaries. Mineralization occurs at shallow depths with some remarkably long intervals. All four boreholes encountered significant equivalent uranium mineralization. While the grades are typically not as high as we saw at Canning during Phase I, they are generally well above average historical grades for the Copper Mountain Project, and the intervals are much longer and shallower than we saw at Canning. We currently see 50 intervals above 100 ppm eU₃O₈, several of them quite long (the longest being 19.96 m (65.49 ft) at 269 ppm from 18 m) with a peak grade of 1,336 ppm eU₃O₈. These estimates remain subject to confirmation by chemical assay and may increase or decrease once disequilibrium, borehole conditions, and laboratory results are assessed. During our Phase I drilling at Canning reported here, chemical assays reported were higher than downhole gamma probe grades by an average of 50% above 500 ppm and 60% above 1,000 ppm. However, the relationship between radiometric equivalent grades and assay grades at Lucky Cliff has not yet been established, and no similar adjustment should be assumed for Lucky Cliff until assay results are received and assessed. Regardless, we consider these to be excellent preliminary results. Because Lucky Cliff sits outside the northern boundary of the Bendix Assessment Area (see Figure 1 and the assessment reported here), and entirely outside any area with a historical uranium resource or endowment estimate, any resource ultimately estimated there will be entirely new and incremental to the Copper Mountain Uranium Project, if supported by sufficient exploration and estimation work."

Lucky Cliff

The Lucky Cliff target area is located about 2,000 metres (6,500 feet) north of the Canning deposit, along the Myrtle's Fault trend. Lucky Cliff was explored by Union Pacific in the late 1970s, but the data was insufficient for the estimation of mineral resources and does not form part of the historical 26.63 Mlb eU₃O₈ estimate reported by Union Pacific at the time (see note on Historical Estimates below). It also falls outside of the Bendix Assessment Area, which was estimated to contain an Exploration Target of between 245 and 655 Mlbs contained within 1,111 Mt to 2,971 Mt (at 100 ppm eU₃O₈) and 222 Mt to 594 Mt (at 500 ppm eU₃O₈), as described here and in the NI 43-101 Technical report. The potential quantity and grade of the Exploration Target are conceptual in nature, there has been insufficient exploration to define a mineral resource, and it is uncertain whether further exploration will result in the Exploration Target being delineated as a mineral resource.

The target area was selected by Union Pacific as a drill target on the basis of favourable geological and geochemical criteria. Several strong N45°E structural trends are present, and the associated rock types are similar to those found at other mineralized occurrences in the project area. A close-spaced (500-foot center) stream sediment sampling program undertaken by Union Pacific identified several highly anomalous (to 118 ppm) zones, and follow-up work was designed to test these anomalies. Ground-truthing of radiometric anomalies by Myriad following the helicopter survey completed late last year identified one point above the target area with a surface measurement of 193.2 ppm eU, using a calibrated RS-230 Handheld Gamma-Ray Spectrometer. Handheld spectrometer readings are preliminary and indicative only, may be affected by environmental and geometric factors, are not assay results, do not measure eU₃O₈ directly, and may not be representative of uranium concentrations in rock samples.

At least twenty holes were drilled by Union Pacific in the late 1970s, and at least 10 holes were reported to have intersected mineralization in excess of 100 ppm eU₃O₈ from depths as shallow as 6 m (20 ft). LK-9 was reported to have intersected 355 ft of 0.027% eU₃O₈ starting at 59 ft, including 207 ft of 0.032% eU₃O₈. LK-11 was reported to have intersected 31 ft of 0.020% at 21.5 ft and 59.5 ft of 0.025% at 83.5 ft. Other reported intersections in this target area included 15.5 ft of 0.055% eU₃O₈ at 55 ft in hole LK-10. Higher grades were reported to be associated with a mafic dyke intruding the main fault zone through the target area. Reported widths are historical downhole widths and true widths are unknown. Equivalent ("e") uranium grades were determined by AEC gamma probes using appropriate calibration factors. No original assay certificates, complete QAQC records, probe calibration records or full original datasets have been reviewed by the Company or the Qualified Person for these historical drill results, and the results should not be relied upon as current exploration results. There is no historical mineral resource estimate for Lucky Cliff.

Myriad selected borehole positions to coincide with similar historical Union Pacific hole positions (the exact historical hole positions are not marked on surface). Thus, LUC0001DD coincides with LK-10; LUC0002DD coincides with LK-9; LUC0003DD coincides with LK-11; and LUC0004DD coincides with LHC-42 (Table 1 and Figure 1). Mineralized intervals for these holes are documented in historical reports, as mentioned above, but original data is not available for verification. Furthermore, only the most significant intervals were mentioned in the historical reports, and no comprehensive summary of intervals is available. Therefore, direct comparison of new and historical grade intervals is not possible.

Table 1: Drilled location details at Lucky Cliff

Figure 1: Drilled locations at Lucky Cliff

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Downhole Logging

Downhole logging was undertaken by Century Geophysical (Century), a respected downhole probe manufacturer and logging company based in Tulsa, Oklahoma and in business since 1946. Century deployed their "Uranium E-Log Suite", which includes Natural Gamma Ray, Resistivity, Spontaneous Potential (S.P.) and Deviation probes. Borehole deviations were additionally measured using a Gyro Deviation tool, which is unaffected by magnetic influence. Century delivered data in electronic format for each hole including log plots and calculated equivalent uranium grades.

Equivalent Uranium Grade Calculations

Century uses its OREGRADE system to convert raw gamma-ray logs into uranium grade estimates expressed as eU₃O₈. The process relies on a trial-and-error iterative deconvolution algorithm to model the distribution of radioactivity from gamma-ray log data. Raw gamma counts are normalized and corrected for borehole conditions by applying dead time correction, geometric multipliers for area-based K-factors and linear depth, and environmental corrections such as water factor below the water table and casing factor within cased sections. The system uses synthetic log creation and iterative interval calculations to estimate eU₃O₈ grades over 15 cm (0.5 foot) intervals. The final output is a grade curve and a printed report that identifies distinct zones and calculates cut-off analyses and best intervals based on grade-thickness product. These estimates remain subject to the limitations of gamma logging and confirmation by laboratory assays.

Historical Resource Estimates

The historical estimate of 26.63 Mlbs eU₃O₈ in 44.1 Mt at 171 ppm eU₃O₈, using a 100 ppm cut-off, was compiled from internal Rocky Mountain Energy Company reports, which are summarised in a report titled "Copper Mountain Exploration Project Report" by Southard, G.G., et. al. (1979). A Qualified Person has not done sufficient work to classify the historical estimate as current mineral resources or mineral reserves, and Myriad is not treating the historical estimate as current mineral resources or mineral reserves.

The historical estimates were completed using polygonal methods based on modelled mineralization geometries. The historical estimates used U.S. Bureau of Mines categories at the time, including terms described as "Inferred" and "Indicated," which are not current CIM terminology and should not be interpreted as current mineral resource categories. Details of the historical resource estimates are available in the current NI 43-101 Technical Report. While the QP has determined that the historical estimates described in this news release are relevant to the Copper Mountain Project Area, are reasonably reliable given the authors and circumstances of their preparation, and are suitable for public disclosure, the estimates are decades old and based on drilling data for which the logs are, as of yet, predominantly unavailable. Readers are cautioned not to place undue reliance on these historical estimates as an indicator of current mineral resources or mineral reserves at the Project Area. Also, while the Copper Mountain Project Area contains all or most of each deposit referred to, some of the resources referred to may be located outside the current Copper Mountain Project Area.

Inherent limitations of the historical estimates include that the nature of mineralization (fracture hosted) makes estimation from drill data less reliable than other deposit types (e.g. those that are thick and uniform). From Myriad Uranium's viewpoint, limitations include that the Company has not been able to verify the original data itself and that the estimates may be optimistic relative to subsequent work which applied a "delayed fission neutron" (DFN) factor to calculate grades. On the other hand, DFN is controversial, in that the approach is viewed by some experts as too conservative. Nevertheless, it was applied in later resource estimations by Union Pacific relating to Copper Mountain. To verify the historical estimates and re-state them as current resources, a program of re-drilling is required to generate new data that can be used to establish the correlation and continuity of geology and grades between boreholes with sufficient confidence to estimate mineral resources.

Qualified Person

The scientific and technical information in this news release, including the eU₃O₈ methodology and historical disclosure, has been reviewed and approved by George van der Walt, MSc., Pr.Sci.Nat., FGSSA, a "Qualified Person" as defined under NI 43-101. Mr. van der Walt is a Principal Consultant with The MSA Group (Pty) Ltd, an independent consultancy, and is independent of the Company for the purposes of NI 43-101. A Qualified Person has not done sufficient work to verify historical exploration results or to classify the historical estimates referred to in this news release as current mineral resources or mineral reserves, and Myriad is not treating such historical estimates as current mineral resources or mineral reserves.

About Myriad Uranium Corp.

Myriad Uranium Corp. holds a 75% interest in the Copper Mountain Uranium Project in Wyoming, USA, with a definitive agreement in place to acquire the remaining 25% via the acquisition of Rush Rare Metals Corp. Copper Mountain hosts multiple historical uranium deposits and past-producing mines, including the Arrowhead Mine (approximately 500,000 lbs U₃O₈ produced). Union Pacific conducted extensive exploration and development in the district during the late 1970s, including approximately 2,000 boreholes and advanced mine planning, before the uranium market downturn in 1980. Union Pacific is estimated to have invested approximately C$125 million (2026 dollars) in the project, generating significant historical resource estimates.

A news release detailing a comprehensive assessment of Copper Mountain's uranium endowment by Bendix Engineering for the US Department of Energy published in 1982 can be viewed here.

Myriad holds a 10% free carried interest in the Red Basin Uranium Project, recently sold to 8VC- and Overmatch-backed Subatomic Industries. Red Basin carries significant historical resource estimates from extensive drilling by Occidental Oil in the late 1970s, and also hosts vanadium, which has been designated a strategic and critical mineral by the U.S. government. Note the caution on historical estimates below.

Myriad's 100%-owned Breccia Pipe Project in Arizona comprises at least 23 breccia pipes that are prospective for uranium and REEs. One of the pipes, the Wate Pipe, was previously owned and explored by Energy Fuels and is the subject of a historical resource estimate. The Breccia Pipe Project has been optioned to Wedgemount Resources (release here).

Note: A qualified person has not done sufficient work to classify the Copper Mountain, Red Basin, and Breccia Pipe Project historical estimates as current mineral resources or mineral reserves, and Myriad is not treating those historical estimates as current mineral resources or mineral reserves. Myriad intends to conduct further work to determine whether the historical estimates can be verified and, if appropriate, supported by current mineral resource estimates.

Forward-Looking Statements

This news release contains "forward-looking information" that is based on the Company's current expectations, estimates, forecasts and projections. This forward-looking information includes, among other things, the Company's business, plans, outlook and business strategy. The words "may", "would", "could", "should", "will", "likely", "expect," "anticipate," "intend", "estimate", "plan", "forecast", "project" and "believe" or other similar words and phrases are intended to identify forward-looking information. The reader is cautioned that assumptions used in the preparation of any forward-looking information may prove to be incorrect, including with respect to the Company's business plans respecting the exploration and development of the Company's mineral properties, the proposed work program on the Company's mineral properties and the potential and economic viability of the Company's mineral properties. Forward-looking information is subject to known and unknown risks, uncertainties and other factors that may cause the Company's actual results, level of activity, performance or achievements to be materially different from those expressed or implied by such forward-looking information. Such factors include, but are not limited to: inability to verify historical data, no assurance of defining mineral resources, permitting, drilling delays and changes in economic conditions or financial markets; increases in costs; litigation; legislative, environmental and other judicial, regulatory, political and competitive developments; and technological or operational difficulties. This list is not exhaustive of the factors that may affect our forward-looking information. These and other factors should be considered carefully, and readers should not place undue reliance on such forward-looking information. The Company does not intend, and expressly disclaims any intention or obligation to, update or revise any forward-looking information whether as a result of new information, future events or otherwise, except as required by applicable law. The CSE has not reviewed, approved or disapproved the contents of this news release.

APPENDIX 1: Preliminary eU₃O₈ Grade Interval Summaries at 100, 200 and 500 ppm thresholds
Reported intervals are downhole lengths; true widths have not yet been determined.

¹ A Qualified Person has not done sufficient work to classify the historical estimate as current mineral resources or mineral reserves, and Myriad is not treating the historical estimate as current mineral resources or mineral reserves. See note about historical estimates.
² The potential quantity and grade of the Exploration Target are conceptual in nature, there has been insufficient exploration to define a mineral resource, and it is uncertain whether further exploration will result in the Exploration Target being delineated as a mineral resource.

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