Noble Plains Uranium Delivers Maiden Resource At Flagship Duck Creek Project In The Powder River Basin, Wyoming

(MENAFN- Newsfile Corp) Noble Plains Uranium Delivers Maiden Resource at Flagship Duck Creek Project in the Powder River Basin, Wyoming

April 23, 2026 9:54 AM EDT | Source: Noble Plains Uranium Corp.

Highlights

Maiden resource estimate prepared in accordance with NI 43-101 standards of 5.32 million pounds Indicated and 1.04 million pounds Inferred - delivered just eight months after closing the Project acquisition. Beat the upper limit of the prior Exploration Target by every key metric: a 30% increase in grade and a 40% increase in GT (grade × thickness) versus the upper limit of the Exploration Target over the mineralized zone in WWC's August 2025 Duck Creek Technical Report. Only half the story told so far: the 2025 drill program covered just 2.5 miles of an approximately 5.25-mile mineralized trend, leaving roughly 2.75 miles of largely untested strike on the Company's expanded claim position. Historical data validated: the recently completed 148-hole drill program successfully confirmed the historical Kerr-McGee intercept data that underpinned the Project's acquisition thesis. Additional drilling planned for 2026 aiming to convert the Exploration Target into resources, extend mineralized strike length, and test the deeper Fort Union Formation. Prime real estate: Duck Creek sits in one of North America's most prolific uranium districts, flanked by projects owned by Cameco Corporation ("Cameco") and Uranium Energy Corp. ("UEC"), two of the largest uranium companies in North America.

Vancouver, British Columbia--(Newsfile Corp. - April 23, 2026) - Noble Plains Uranium Corp. (TSXV: NOBL) (OTCQB: NBLXF) (FSE: INE0) (" Noble Plains " or the " Company "), a U.S.-focused uranium exploration and development company, is pleased to announce a maiden mineral resource estimate prepared in accordance with National Instrument 43-101(" NI 43-101 ") standards for its flagship Duck Creek Project (" Duck Creek " or the " Project ") in Wyoming's Powder River Basin. The estimate, prepared by WWC Engineering (" WWC ") of Sheridan, Wyoming, follows the Company's successful drilling campaign and represents a foundational milestone for Noble Plains.

"Today's resource announcement is a defining moment for Noble Plains and, importantly, one we've delivered in well under a year from the day we closed on Duck Creek. Our thesis was simple: take a historically drilled, brownfield uranium asset in one of the best uranium addresses in North America, execute with discipline and efficiency to convert it into compliant pounds. With a maiden resource now on the books, we've done exactly that and, in the process, have been able to outperform our own exploration target on grade, thickness, and total pounds," stated Drew Zimmerman, CEO of Noble Plains. "What I want investors to take away is that this resource is a starting point, not a finish line. We've drilled roughly half of the mineralized trend on our expanded land package, we have an additional Exploration Target to grow into, and we still have an entirely separate formation in the Fort Union, that we believe could host significant additional potential. Duck Creek sits between projects held by Cameco and UEC, two of the largest uranium companies in North America, and with uranium demand being driven by a new nuclear renaissance, AI and data center power demand build-out, and a clear policy push for domestic U.S. supply, we believe the timing for a scalable American uranium project could hardly be better. This resource is another milestone in our plan to build a meaningful, resource-backed uranium platform and we intend to keep stacking milestones."

Duck Creek Mineral Resource Estimate - as of 12 February 2026:

Resource Classification	Average Grade (%U 3 O 8 )	Average GT	Tons (000s)	U 3 O 8 (Mlbs)
Indicated	0.06	0.78	4,290	5.32
Inferred	0.09	1.16	839	1.04

Notes: ISR resources were determined using the GT Sum Contour Method and met the following criteria:

Based on grade cutoff of 0.020% eU3O8, a grade x thickness (GT) cutoff of 0.20 GT and a one-foot minimum intercept thickness. Intercept data within the "E" Sand was combined and summed together to calculate a GT sum used for classified resource calculations. Indicated and Inferred mineral resources as defined in Section 1.2 of NI 43-101 (the CIM Definition Standards [CIM Council, 2014]). All reported resources occur below the static water table. Average grades are calculated as weighted averages.

"The recently completed Duck Creek drill program focused on a 2.5 miles length of the mineralized trend and was a huge success for the Company, delivering a 30% increase in the grade and a 40% increase in the GT above the upper limit of the Exploration Target estimated in WWC's August 2025 Duck Creek Technical Report," stated Paul Cowley, COO of Noble Plains. "Significant upside remains on the approximately 2.75 miles of mineralized trend that have yet to be drilled on our expanded claim position, with the system apparently continuing to both the north and south as evidenced by historic drill locations and a string of shallow historic open pits from the 1970s and 1980s. It is on this basis that WWC defined an Exploration Target alongside the maiden resource, providing a clear, data-supported roadmap for our 2026 drill program. Equally encouraging, our 2025 drilling has already demonstrated that mineralization extends below some of the shallow historic open pits, pointing to additional potential that was never pursued by the historical operators. All of the foregoing pertains to the Wasatch Formation; beneath it, the Company believes the Fort Union Formation represents a significant and largely untested opportunity for additional uranium mineralization, effectively offering a third, independent growth vector at Duck Creek."

Furthermore, an Exploration Target for the Project is estimated at between 941 and 1,021 thousand tons grading between 0.020% and 0.052% U3O8. The Exploration Target was prepared by WWC Engineering and is based on historical Kerr-McGee drill hole intercept data and trend mapping covering approximately 2.75 miles of mineralized strike on the Company's expanded claim position that lies outside of, and along strike from, the area covered by the maiden mineral resource estimate. The lower and upper limits of the tonnage and grade ranges were derived by applying the GT Sum Contour Method to the historical intercept dataset, using the same parameters adopted for the maiden resource estimate: a grade cutoff of 0.020% eU3O8, a GT cutoff of 0.20, and a one-foot minimum intercept thickness, with tonnage calculated using a bulk density of 16.6 ft³/ton. The Exploration Target relates exclusively to the Wasatch Formation and does not include any potential of the underlying Fort Union Formation.

The potential quantity and grade of the Exploration Target is conceptual in nature as exploration in these areas is insufficient to estimate a mineral resource. It is uncertain if further exploration will result in the Exploration Target being delineated as a mineral resource.

Figure 1 - Duck Creek Project

To view an enhanced version of this graphic, please visit:

The NI 43-101 resource estimate was prepared by WWC Engineering and authored by Christopher McDowell, P.G., a registered member of the Society for Mining, Metallurgy & Exploration (Member No. 4311521) and a Qualified Person (" QP "). The full technical report will be filed on SEDAR+ at and Noble Plains website within 45 days of the issuance of this news release.

Data Verification
Canadian Institute of Mining Metallurgy and Petroleum (" CIM ") Definition Standards require an assessment of the historical and recent data used to classify resources at Duck Creek. This analysis demonstrated that both the historical and recent data, as well as their interpretation, were developed by reputable and experienced uranium exploration companies with appropriately qualified staff experienced in uranium exploration.

Available data from historical drilling and exploration included drilling maps and intercept data sheets. Historical mineral trend maps were cross-checked against intercept data sheets. Ten percent of the tabulated mineral intercept values were reviewed and found to be valid.

Recent exploration includes a 148-hole exploration drilling project completed by Noble Plains. Both historical and recent data were used to complete the mineral resource estimate and the recent drilling data were also used to verify the historical data. Numerous holes were drilled in 2025 that were very close in proximity to historical drill holes. The recent drilling not only followed the same trends as the historical drilling, but also produced mineral intercept data similar in depth, thickness, and grade, thereby validating the historical results.

The QP has adequately verified the historical and recent data for the Duck Creek Project. The QP has reviewed the data validation process and finds the drillhole database to be sufficient and adequate for resource estimation. The QP concludes the work done by Noble Plains to verify the historical data has validated the Project information used to calculate the resource estimate.

Qualified Person
Christopher McDowell, P.G., a registered member of the Society for Mining, Metallurgy & Exploration (Member No. 4311521), Project Manager at WWC Engineering, is the QP as defined in Canadian National Instrument 43-101, who has read and approved the technical content of this news release.

Risks and Factors That May Materially Affect the Mineral Resource Estimate
The mineral resource estimate disclosed in this news release is subject to a number of known risks and uncertainties that could materially affect its potential development, including:

Permitting and regulatory approvals. The Project does not currently hold the permits and authorizations required to conduct in-situ recovery ("ISR") uranium operations. Advancement to development will require, among other approvals, a source materials license (administered by the State of Wyoming as an Agreement State of the U.S. Nuclear Regulatory Commission), a Permit to Mine from the Wyoming Department of Environmental Quality - Land Quality Division, Class III underground injection control permits and an aquifer exemption from the U.S. Environmental Protection Agency or its state-delegated authority, and water rights authorizations from the Wyoming State Engineer's Office. There is no assurance that any or all of these approvals will be obtained on a timely basis or at all, or on terms acceptable to the Company. Amenability to ISR. The Classification of mineralization at the Project as ISR-amenable is preliminary. Confirmation of ISR amenability will require additional hydrogeological characterization (including pump testing, water chemistry analysis, and confirmation of confined aquifer conditions), as well as bottle-roll or column leach metallurgical testing. Adverse results from this testing could materially reduce the portion of the resource that is ultimately economically recoverable. Operations. Operational risks such as reagents, power, labor and/or material cost fluctuations exist and could impact development and future operations. Surface access and land tenure. The Project is held through a combination of unpatented mining claims and other surface and mineral interests. Maintenance of claim title requires ongoing payment of federal maintenance fees and compliance with state and federal regulations. Surface access for drilling and development may require negotiation of surface use agreements with surface owners, where mineral and surface estates are split. Bonding and financial assurance. Future ISR operations will require posting of reclamation, restoration, and long-term groundwater monitoring bonds with state and federal regulators. The amount of financial assurance required is determined by the regulator and could be material. Uranium market and commodity price. The resource is sensitive to the uranium price, which has historically been volatile and is influenced by factors outside the Company's control. Estimation risk. Mineral resource estimates are inherently uncertain and may require revision as additional drilling, sampling, and technical information becomes available. Inferred mineral resources, in particular, are based on limited information and may not be upgraded to the indicated or measured categories.

About Noble Plains Uranium
Noble Plains Uranium Corp. is a U.S.-focused uranium exploration and development company advancing a portfolio of high-potential projects amenable to In Situ Recovery (ISR) - the most capital-efficient and environmentally responsible method of uranium extraction. Our strategy targets historically drilled and underexplored assets in proven jurisdictions, with the objective of rapidly delineating NI 43-101 compliant resources and building a scalable inventory of domestic uranium.

On Behalf of the Board of Directors,

"Drew Zimmerman", CEO & President

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