Radisson Mining Resources Inc. (TSX-V: RDS) (OTCQX: RMRDF) is pleased to announce the results of three new drill holes recently completed at its 100%-owned O’Brien Gold Project located in the Abitibi region of Québec. The three holes are from separate areas of exploration focus within the ongoing 140,000 metre step-out drill program. The results include the highest drill assay ever achieved in the Project’s history: 1,603.95 grams per tonne gold over 1 metre within a mineralized interval of 316.31 g/t Au over 5.1 metres (core lengths). This record-setting intercept is in hole OB-26-385W4, which was targeting the deep extension of vein mineralization hosted within Piché Group rocks beneath the former mine workings. The intercept, characterized by extensive visible gold (Figure 1), was observed in Pontiac Formation rocks at 823 metres downhole, before the target area was reached. It represents, potentially, a new zone of very high-grade mineralization, outside the scope of the main mineral resources and previously unrecognized. Highlights of the three holes released today (Figure 2 and Table 1) include:

• O’Brien Mine East: OB-26-385W4 intersected 316.31 g/t Au over 5.1 metres (core length) including 1,603.95 g/t Au over 1.0 metre and 3.97 g/t Au over 5.0 metres including 10.47 g/t Au over 1.3 metres.
• Trend #1: OB-26-384W1 intersected 46.22 g/t Au over 3.9 metres including 132.28 g/t Au over 1.3 metres and 2.72 g/t Au over 17.5 metres including 10.81 g/t Au over 2.0 metres and 2.39 g/t Au over 29.0 metres including 6.08 g/t Au over 2.5 metres.
• Trend #1-Trend #2 Gap: OB-26-386W3 intersected 8.60 g/t Au over 2.6 metres including 13.87 g/t Au over 1.5 metres and 2.74 g/t Au over 11.4 metres including 14.64 g/t Au over 1.1 metres.

Matt Manson, President and CEO: “We are taking the unusual step of releasing three holes from our ongoing step-out drill program at O’Brien because of the significant nature of the results received. The former O’Brien Gold Mine had a reputation for extremely high-grade gold mineralization. Recall that in December 2024 we released a drill intercept of 1,345 g/t Au over 1.0 metre (within 643 g/t Au over 2.0 metres) interpreted as the extension of the famous O’Brien “Jewellery Box” mining stope (see Radisson news release dated December 9, 2024). Now, this result has been exceeded with 1,604 g/t Au over 1.0 metre (within 316 g/t Au over 5.1 metres) from a new mineralized zone hosted within Pontiac meta-sedimentary rocks, the formation that forms the hanging wall of the Piché rocks that host both the bulk of the Project’s gold mineralization and the former mine workings. Importantly, it occurs within a cluster of previously published gold intercepts, offering the potential for a new, very high-grade zone of mineralization outside of the scope of the Project’s current mineral resources. Also in this news release, drill hole OB-26-384W1 has returned multiple intercepts of high-grade mineralization in classic quartz vein/alteration packages at the Project’s Trend #1, filling in the deep extension of this important target area between 1,600 and 1,700 metres depth. Together, the results published today reinforce three key exploration themes at O’Brien: the potential for new high-grade mineralization in Pontiac rocks; continued extension of O’Brien gold mineralization and mineral resources at depth, and; additional mineralization within previously under-drilled gaps. Drilling continues with eight rigs active.”

Radisson will be hosting a technical webinar on Tuesday July 14^th at 10.00am EST hosted by Matt Manson, President & CEO, David Ross, VP Exploration, and Hubert Parent-Bouchard, CFO to provide further details on the ongoing exploration program at the O’Brien Gold Project. Interested participants may register here.

Figure 1: Top: OB-26-385W4. 1,603.95 g/t Au over 1.0 metre (within 316.31 g/t Au over 5.1 metres). Bottom: OB-26-384W1 132.28 g/t Au over 1.3 metres (within 46.22 g/t Au over 3.9 metres)

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. 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 centimetres up to several metres in thickness and are associated with broader, mineralized alteration envelopes. 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 steeply plunging grade shoots developed over significant lengths.

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 metres. Modern exploration has focussed on delineating well-developed vein mineralization below and to the east of the historic mine. 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.

Figure 2: Longitudinal Vertical Section and Plan View of Gold Vein Mineralization and Mineral Resources at the O’Brien Gold Project, with Today’s Drill Holes Illustrated

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 gold mineralization at the Project. This drilling is accomplished with pilot holes followed by wedges and directional drilling to maximize drill efficiency and minimize costs. In October 2025, Radisson announced the expansion of the step-out drill program to 140,000 metres employing eight drill rigs (see Radisson news release dated October 16, 2025).

Table 1: Assay Results from Select Drill Holes

Notes on Calculation of Drill Intercepts:

The O’Brien Gold Project Mineral Resource Estimate effective January 31, 2026 utilizes a 2.20 g/t Au bottom cut-off, a US$2,500 gold price, a minimum mining width of 1.2 metres, and a 60 g/t Au upper cap on individual assays. Intercepts presented in Table 1 are calculated with a 3.00 g/t Au bottom cut-off. Sample grades are uncapped. True widths, based on depth of intercept and drill hole inclination, are estimated to be 30-80% of core length. Table 3 presents additional drill intercepts calculated with a 1.00 g/t Au bottom cut-off over a minimum 1.0 metre 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 and Greywackes; POR-S, POR-N: Porphyry South, North; TX: Crystal Tuff; ZFLLC: Larder Lake-Cadillac Fault Zone

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 metres, including 242.0 g/t Au over 1.0 metre at approximately 1,500 metres vertical depth (see Radisson news release dated December 16, 2024). Fifteen wedge branches were completed from OB-24-337 delineating up to eight gold-bearing veins over a 250-metre by 700-metre area in what is referred to as “O’Brien Mine East” (Figure 2; see Radisson news release dated February 12, 2026). In March 2026, Radisson published an interim update in the Project’s mineral resources, showing meaningful growth based on the on-going drilling (see Radisson news release dated March 2, 2026).

The focus of the step-out drill program has been the extension of mineralization at depth, with an exploration floor of 2 kilometres depth, and recently announced plans to extend this drilling to 2.5 kilometres depth (see Radisson news release dated May 28, 2026). Given the character of neighbouring gold deposits and the wealth of mining infrastructure within or close to the O’Brien Gold Project, Radisson believes that significant exploration potential exists to these depths, and such mineralization might reasonably be expected to be developed.

In today’s results, drill hole OB-26-385W4 was the fourth wedge from the pilot hole targeting the O’Brien Mine East area between the base of the former mine and the OB-24-337 wedge cluster (Figure 2 and Table 1). The record intercept of 1,603.95 g/t Au over 1.0 metre (within 316.31 g/t Au over 5.1 metres) was returned from a mineralized zone within Pontiac Formation rocks starting at 823 metres downhole. The extremely high-grade nature of the intercept is potentially due to the intersection of a localised fold that produces the dramatic core-parallel gold mineralization illustrated in Figure 1.

Figure 3: Vertical Section Through “O’Brien Mine East” with Today’s New Drill Results

The Pontiac Formation is known to host significant gold deposits elsewhere within Québec’s Abitibi region. While the bulk of the Project’s Mineral Resources are hosted within Piché Group rocks, gold mineralization and mineral resources have been defined previously in both the Pontiac and Cadillac metasedimentary rocks in the hanging wall and footwall respectively of the Piché and the LLCB. The new intercept is not isolated but appears spatially related to a cluster of previously reported gold intercepts, including from OB-24-337W13 which returned 90.60 g/t Au over 1 metre (within 30.59 g/t Au over 3.0 metres) as close as 45 metres down dip from the new intercept (Figure 3). The intercepts warrant follow-up as they indicate the potential for a new, very high-grade mineralized zone within the Pontiac, approximately 180 metres from the Pontiac-Piché contact at approximately 700 metres vertical depth, and outside the scope of the current mineral resources.

Also in today’s results, drill hole OB-26-384W1 is the first wedge completed on the deep pilot hole OB-26-384 testing the deep extension of the Project’s Trend #1 (Figure 2). This hole returned at least three significant zones of classic O’Brien quartz-sulphide-gold veins within alteration envelopes (Figure 2 and Table 1) between 1,600 and 1,700 metres depth. Within the LLCB itself, the hole returned 46.22 g/t Au over 3.9 metres including 132.28 g/t Au over 1.3 metres with significant visible gold (Figure 1). Recall that pilot hole OB-26-384 was the deepest hole ever drilled at the Project and returned multiple zones of mineralization at 1,900 metres depth (see Radisson news release dated April 30, 2026), such as 4.54 g/t Au over 12.0 metres including 16.85 g/t Au over 1.0 metre and including 12.87 g/t Au over 1.0 metre. These two holes taken together are confirming the deep extension of the O’Brien mineralizing system several hundred metres below the base of the current Mineral Resources at Trend #1, with significant implications for the Project.

In addition to the progressively deeper drilling, the 140,000-metre program includes targeting of areas within the O’Brien geological model that have not previously been tested and offer the potential for additional mineral resources at shallower depths. This includes the “gaps” created between mineralized trends that are typically defined by a lack of drilling rather than a lack of mineralization. Recent drill results have indicated significant mineralization within the important “Trend 1-Trend 2 Gap” (see Radisson news release dated June 1, 2026 and June 22, 2026). Today’s release includes another example of strong mineralization in this area, with OB-26-386W3 exhibiting at least two characteristic zones of quartz-sulphide-gold veins within alteration envelopes (Figure 2 and Table 1). Currently, the large “Trend 0 Gap” is being tested with a new deep pilot hole set up to approach from the north due to access considerations. If successful, this pilot hole will be used to give wide coverage of this previously undrilled area with multiple wedge branches and directional drilling.

Taken together, these latest three drill holes at the Project continue to demonstrate the very high incidence of intercepts with grades and thicknesses consistent with the Project’s mineral resources (“hits”, per Table 2). This now stands at 81% of all drill holes completed to date, an impressive result for a step-out drill program specifically targeting non-resource areas (Figure 4). Mineralization remains open in every direction, with clear opportunities to expand the quantity of new mineral resources, in particular by drilling at depth.

Figure 4: Deep Step-Out Drill Holes Completed and/or Published by the Company Since March 2026

Table 2: Drill Results Published for the O’Brien Gold Project Since December 2024

Table 3: Detailed Assay Results (see “Notes on Calculation of Drill Intercepts”)

Table 4: Drill Hole Collar Information for Holes contained in this News Release

Notes:
Hole lengths for wedges represent meterage from point of wedge.

QA/QC

All drill core in this campaign is NQ in size. Assays were completed on sawn half-core, with the second half retained in the core box for future reference. Geologists mark cut lines on the core perpendicular to the foliation. The half on the right side of the saw blade is bagged for the laboratory and the left half is retained as reference. Sample bags are sealed, placed in rice sacks, plastic-wrapped on pallets, and held in a secure facility until pick-up by the laboratory’s dedicated truck.

Samples are delivered to MSALABS’ analytical laboratory in Val-d’Or, Québec, for preparation and gold analysis. The entire sample is dried and crushed (70% passing a 2-millimetre sieve) and split to 500 g. Gold analysis is performed on an approximately 500 g aliquot (a single jar) using Chrysos PhotonAssay technology. Mineralized zones containing visible gold, plus additional intervals selected at the discretion of the logging geologist, are analyzed to extinction, whereby the entire sample is split into multiple ~500 g jars, each jar is analyzed by PhotonAssay, and the weighted average of the results is used for reporting. A one-metre sample typically requires five jars.

Certified reference materials (CRMs), blank samples, and reject duplicates are inserted for quality assurance and quality control. Either a CRM, a blank, or a duplicate is inserted during regular sampling at a rate of 1 per 25 samples, with the insertion rate increased for intervals selected for assay to extinction. Four different CRMs are in use with an appropriate range of certified grades suited for O’Brien mineralization. Jars of CRM material are stored at the laboratory and inserted into the sample stream as directed by Radisson. The CRMs were selected by Radisson in accordance with Chrysos Corporation’s best-practice guidelines for PhotonAssay. Blanks consist of commercially obtained crushed quartzite known to be barren of gold. Samples returning results greater than 1 g/t Au are also fire assayed.

MSALABS operates under ISO/IEC 17025 accreditation, utilizing industry-standard QA/QC frameworks for gold analysis. Through the integration of blanks, duplicates, and CRMs into its workflow, the laboratory adheres to established benchmarks that ensure precise, reliable, and verifiable results.

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.

About Radisson Mining

Radisson is a gold exploration company focused on its 100% owned O’Brien Gold Project, located in the Bousquet-Cadillac mining camp along the world-renowned Larder-Lake-Cadillac Break in Abitibi, Québec. A July 2025 PEA described a low cost and high value project with an 11-year mine life and significant upside potential based on the use of existing regional infrastructure. Indicated Mineral Resources are estimated at 0.63 Moz (3.49 Mt at 5.59 g/t Au), with additional Inferred Mineral Resources estimated at 1.69 Moz (10.37 Mt at 5.08 g/t Au). Please see the NI 43-101 “O’Brien Gold Project Technical Report and Preliminary Economic Assessment, Québec, Canada” effective June 27, 2025, Radisson’s news release dated March 2, 2026 “With Step-Out Drilling Continuing, Radisson Demonstrates Meaningful Resource Growth at O’Brien with an Updated Mineral Resource Estimate” and other filings made with Canadian securities regulatory authorities available at www.sedarplus.ca for further details and assumptions relating to the O’Brien Gold Project.