Radisson Announces Additional High-Grade Drill Results and Further Extends New Mineralization Beneath the Historic O'Brien Gold Mine

Radisson Mining Resources Inc. ("Radisson") is pleased to announce assay results from six new drill holes completed at its 100 %-owned O'Brien Gold Project ("O'Brien") located in the Abitibi region of Québec. The six holes are the latest completed as part of the Company's ongoing 140,000-meter step-out drill program designed to test the overall scope of gold mineralization at the Project (see Radisson news release dated October 16, 2025). Two of the holes represent the twelfth and thirteenth directional wedges completed from pilot hole OB-24-337 and serve to expand the broad area of new high-grade mineralization being delineated across multiple veins beneath the historic O'Brien Gold Mine. All six of the holes released today intersected gold mineralization, and five of the holes returned intercepts with grades and thicknesses consistent with the Project's existing mineral resources, continuing the very high success rate of the current drill program.

Highlights include:

• OB-25-337W13 intersected 90.60 grams per tonne ("g/t") gold ("Au") over 1.0 meter within a mineralized interval averaging 30.59 g/t Au over 3.0 meters and 9.14 g/t Au over 2.7 meters, including 16.35 g/t Au over 1.4 meters;
• OB-25-337W12 intersected 25.10 g/t Au over 1.5 meters and 14.20 g/t Au over 1.5 meters and 11.40 g/t Au over 1.3 meters;
• OB-25-322W2 intersected 3.11 g/t Au over 8.0 meters including 5.93 g/t Au over 1.5 meters and 3.62 g/t Au over 4.0 meters including 6.33 g/t Au over 1.5 meters;
• OB-25-322W1 intersected 4.02 g/t Au over 4.5 meters, including 8.29 g/t Au over 1.5 meters;

Matt Manson, President and CEO: "Today we are releasing six new drill holes from our ongoing deep step-out drill program at O'Brien. These continue to illustrate the extension of the Project's system of gold mineralization below the historic O'Brien mine and the current mineral resources. Of particular note are the two new wedges completed from pilot hole OB-24-337 located beneath the former mine's final stope. These are the twelfth and thirteenth such wedges completed. Once again, we are seeing multiple high-grade intercepts of quartz-sulphide veins within broader alteration envelopes. This represents a system of gold mineralization that we have modelled as up to six veins delineated over a 250-meter (east-west) by 500-meter (vertical) area that remains open. With this step-out drill program we are steadily pushing the limits of known mineralization at O'Brien outwards and downwards. Overall, we have now completed 74 drill holes in the 140,000 meters program, 61 of which have intersected mineralization with grades and thicknesses consistent with the Project's current mineral resources, an 82 % success rate. As we start 2026, we will be operating seven drill rigs at site and ramping up to our eighth rig presently. Twelve additional step-out drill holes, including the final OB-24-337 wedges, have been completed and are awaiting assays."

Table 1. Assay Results from Select Drill Holes

Notes on Calculation of Drill Intercepts:

The O'Brien Gold Project Mineral Resource Estimate effective May 6, 2025 ("MRE") utilizes a 2.20 g/t Au bottom cut-off, a US$2,000 gold price, a minimum mining width of 1.2 meters, and a 40 g/t Au upper cap on composites. Intercepts presented in Table 1 are calculated with a 3.00 g/t Au bottom cut-off. True widths, based on depth of intercept and drill hole inclination, are estimated to be 30-80 % of core length. Table 2 presents additional drill intercepts calculated with a 1.00 g/t bottom cut-off over a minimum 1.0 meter core length so as to illustrate the frequency and continuity of mineralized intervals within which high-grade gold veins at O'Brien are developed. Lithology Codes: PON-S3: Pontiac Sediments; V3-S, V3-N, V3-CEN: Basalt-South, North, Central; S1P, S3P: Conglomerate; POR-S, POR-N: Porphyry South, North; TX: Crystal Tuff; ZFLLC: Larder Lake-Cadillac Fault Zone.

Gold Mineralization at O'Brien

Gold mineralizing quartz-sulphide veins at O'Brien occur within a thin band of interlayered mafic volcanic rocks, conglomerates, and porphyritic andesitic sills of the Piché Group occurring in contact with the east-west oriented Larder Lake-Cadillac Break ("LLCB"). Gold, along with pyrite and arsenopyrite, is typically associated with shearing and a pervasive biotite alteration, and developed within multiple Piché Group lithologies and, occasionally, the hanging-wall Pontiac and footwall Cadillac meta-sedimentary rocks.

As mapped at the historic O'Brien mine, and now replicated in the modern drilling, individual veins are generally narrow, ranging from several centimeters up to several meters in thickness. Multiple veins occur sub-parallel to each other, as well as sub-parallel to the Piché lithologies and the LLCB. Individual veins have well-established lateral continuity, with near-vertical, high-grade shoots developed over significant lengths. Based on the historic data available, it is clear that the former mine was "high-graded", with mining focussed on a main central stope and parallel veins identified but left undeveloped.

The historic O'Brien mine produced over half a million ounces of gold from such veins and shoots at an average grade exceeding 15 g/t Au and over a vertical extent of at least 1,000 meters. Modern exploration has focussed on delineating well developed vein mineralization to the east of the historic mine, with additional high-grade shoots becoming evident in the exploration data over what has been described as a series of repeating trends ("Trend #s 0 to 5").

Figure 2. Deep Step-Out Drill Holes Completed and/or Published by the Company since December 2024. Image Credit: Radisson Mining Resources Inc.

Step-Out Drilling at O'Brien

Since the end of 2024, Radisson has been pursuing a program of broad step-outs beneath the historic O'Brien Gold mine and the existing mineral resources designed to test the extent of mineralization at the Project. This drilling is accomplished with pilot holes followed by wedges and directional drilling to maximize drill efficiency. On October 16, 2025, Radisson announced the expansion of the step-out drill program to 140,000 meters employing an eventual eight drill rigs.

The origin of the step-out drill program was the deep pilot hole OB-24-337, which was the first exploration drill hole located below the former mine workings since mining ended in 1957. This hole intersected 31.24 g/t Au over 8.0 meters, including 242.0 g/t Au over 1.0 meter at approximately 1,500 meters vertical depth (see Radisson news release dated December 16, 2024). With today's results, assay results from a total of thirteen wedges from OB-24-337 have now been reported and up to six gold-bearing veins have been delineated over an area of approximately 250 meters (east-west) by 500 meters (vertical). The thirteenth wedge, released today, intersected 9.14 g/t Au over 2.7 meters including 16.35 g/t Au over 1.4 meters within Piché rocks just 40 meters below the final historic mining stope (Figures 1 and 3). The final two wedges, the fourteenth and fifteenth, have been completed and assay results are expected shortly. Future drilling in this area will utilize new pilot holes and wedge extensions to test the full scope of mineralization down to 2 kilometers depth.

Figure 3. Vertical Cross Section through the Historic O'Brien Mine with Deep Pilot Hole OB-24-337 and Wedges OB-25-337W1 to W13.  Image Credit: Radisson Mining Resources Inc.

Table 2. Detailed Assay Results (see "Notes on Calculation of Drill Intercepts")

Table 3. Drill Hole Collar Information for Holes contained in this News Release

Notes:

Hole lengths for wedges represent meterage from point of wedge. Drill hole OB-24-337 was completed in 2024 while its wedge branches were drilled in 2025.

Today's results also include the first and second wedges completed from pilot drill hole OB-24-322, which intersected high-grade mineralization on the downwards extension of Trend #1 at 1,280 meters and 1,360 meters vertical depth, respectively. These two wedges appear to have intersected the same mineralized zone over a vertical separation of 80 meters, returning similar intercepts of 4.02 g/t Au over 4.5 meters, including 8.29 g/t Au over 1.5 meters (OB-25-322W1) and 3.11 g/t Au over 8.0 meters including 5.93 g/t Au over 1.5 meters and 3.62 g/t Au over 4.0 meters including 6.33 g/t Au over 1.5 meters (OB-25-322W2). Additional drill wedges from OB-24-322 have been completed and assays are pending.

Drill hole OB-25-371W7 is the seventh wedge from a pilot hole centered on the deep extension of Trend #2. It returned three separate intercepts of gold mineralization that were short, but with grades and thicknesses consistent with the Project's mineral resources, in an untested area on the western side of Trend #2 towards the deep extension of Trend #1 (Figure 1). The Company considers the apparent "gap" between the deep extensions of these two mineralizing trends to be a function of drill coverage rather than mineralization (Figure 2). This area offers a significant opportunity to delineate future mineral resources at relatively shallow depths and within the scope of the mine design contained in the Project's 2025 Preliminary Economic Assessment. Further drill testing here will be an important part of the upcoming 2026 work program. The sixth drill hole release today, OB-25-377, was located in a gap area between the western and eastern portions of the former mine and intersected three narrow zones of minor mineralization.

QA/QC

All drill cores in this campaign are NQ in size. Assays were completed on sawn half-cores, with the second half kept for future reference. The samples were analyzed using standard fire assay procedures with Atomic Absorption (AA) finish at ALS Laboratory Ltd, in Val-d'Or, Quebec. Samples yielding a grade higher than 10 g/t Au were analyzed a second time by fire assay with gravimetric finish at the same laboratory. Mineralized zones containing visible gold were analyzed with metallic sieve procedure. Standard reference materials, blank samples and duplicates were inserted prior to shipment for quality assurance and quality control (QA/QC) program.

QP Disclosure

Disclosure of a scientific or technical nature in this news release was prepared under the supervision of Mr. Richard Nieminen, P.Geo, (QC), a geological consultant for Radisson and a Qualified Person for purposes of NI 43-101. Mr. Luke Evans, M.Sc., P.Eng., ing, of SLR Consulting (Canada) Ltd., is the Qualified Person responsible for the preparation of the MRE at O'Brien. Each of Mr. Nieminen and Mr. Evans is independent of Radisson and the O'Brien Gold Project.