Troilus Drills 157.5 Metres Grading 0.95 g/t AuEq While Targeting Inferred Material Within the Z87 Reserve Pit

MONTREAL, June 25, 2026 (GLOBE NEWSWIRE) — Troilus Mining Corp. (“Troilus” or the “Company”) (TSX: TLG; OTCQX: CHXMF; FSE: CM5), is pleased to announce the first batch of results from the Z87 optimization drill program, as part of its ongoing 2026 Exploration activities at its Troilus Project located in north-central Quebec, Canada. The results reported include 13 drill holes totalling 3,718 metres, following the exploration program outlined in the Company’s March 31, 2026 press release.

The ongoing Z87 optimization program is designed to support future mine planning by targeting inferred mineralization and previously unsampled intervals from historic drilling within the hangingwall of the main ore zone. All results reported today are located within the Z87 reserve pit, as defined in the Feasibility Study (see May 14, 2024 press release), and support the Company’s objective of evaluating opportunities to improve future mine planning, including potential resource conversion, pit sequencing optimization, strip ratio improvements and early-year mill feed flexibility.

Z87 Intercept Highlights (see Figure 1):

• Hole 87-26-505 intersected 0.95 g/t gold equivalent (“AuEq”) (0.82 g/t Au, 0.88 g/t Ag, 0.08 % Cu) over 157.7 m, including 1.37 g/t AuEq (1.28 g/t Au, 0.99 g/t Ag, 0.04 % Cu) over 28 m, also including 1.68 g/t AuEq (1.47 g/t Au, 0.91 g/t Ag, 0.12 % Cu) over 30.9 m, and also including 1.16 g/t AuEq (0.87 g/t Au, 1.54 g/t Ag, 0.17 % Cu) over 19 m starting at 238 m downhole. See Figure 2.
• Hole 87-26-508 intersected 1.10 g/t gold equivalent (“AuEq”) (0.90 g/t Au, 2.06 g/t Ag, 0.11 % Cu) over 96 m, including 2.59 g/t AuEq (2.28 g/t Au, 2.48 g/t Ag, 0.18 % Cu) over 13.7 m, also including 1.88 g/t AuEq (1.60 g/t Au, 3.10 g/t Ag, 0.15 % Cu) over 16.5 m starting at 284 m downhole. See Figure 3.
• Hole 87-26-481 intersected 0.55 g/t gold equivalent (“AuEq”) (0.49 g/t Au, 0.34 g/t Ag, 0.03 % Cu) over 83 m, including 1.10 g/t AuEq (1.02 g/t Au, 0.43 g/t Ag, 0.05 % Cu) over 20 m starting at 298 m downhole. See Figure 4.

Justin Reid, CEO of Troilus, commented, “The drill bit continues to deliver exciting results from within the reserve pit areas, and the Z87 program is steadily advancing exactly what it was designed to do. By targeting historically unsampled intervals in the hangingwall, upgrading inferred material and improving our understanding of mineralization within and around the existing pit shell, we are working to unlock opportunities that were not fully captured in previous drilling campaigns. Much of the hangingwall in Z87 was left unsampled during historical drill campaigns, creating gaps in the block model that we believe represent an important optimization opportunity. These initial results support our view that additional mineralized material may be better defined in this area, with the potential to enhance future sequencing, improve strip ratios and provide greater flexibility for early-year feed to the planned 50,000 tonne-per-day operation.”

Z87 was one of two zones previously mined by open pit at the Troilus Project. Many of the historic drill holes that defined the previously mined reserve were not fully sampled, with several hundred metres of core left unsampled in many holes. For resource estimation purposes, these unsampled intervals are assigned a value equal to half the laboratory analysis detection limit, resulting in large gaps within the block model.

The current Z87 optimization drill program was designed to target these gaps and convert waste to potential future ore. There also exist opportunities to upgrade the classification of inferred material to the indicated category, which could allow for potential incorporation into future mine plan updates.

All grades are uncut, and true thicknesses are approximately 75% to 90% of drilled length.

*The completed NI 43-101 technical report associated with the Troilus Project FS can be found on SEDAR+ at www.sedarplus.ca under the Company’s issuer profile or on the Company’s website at www.troilusgold.com

Figure 1. Plan Map with Reported Drill Hole and Cross Section Locations from Z87

Figure 2. Cross section showing results for drillhole 87-26-505.

Figure 3. Cross section showing results for drillhole 87-26-508 and 87-26-509.

Figure 4. Cross section showing results for drillhole 87-26-481.

Z87 Drilling

Drillhole 87-26-505 was designed to target an area of inferred material within the Z87 reserve pit and test for additional mineralization in the hangingwall of the main zone. In the Hangingwall, the hole returned 0.99 g/t AuEq over 17 metres from an area of the resource model that does not currently contain mineralized material (Figure 2), highlighting the potential to help improved strip ratios within the Phase 1 Z87 reserve pit – an area of significant mining activity during the critical early years of production. The hole also returned a broad main-zone intercept of 157.5 metres grading 0.95 g/t AuEq. From a grade x width perspective, this intercept is among the best results returned from drilling since the Company commenced exploration in 2018. This interval contained higher-grade sections grading 1.37 g/t AuEq over 28 metres, 1.68 g/t AuEq over 30.9 metres and 1.16 g/t AuEq over 19 metres. By targeting inferred material within the reserve pit, the program is evaluating opportunities to upgrade mineralization to the indicated category for potential incorporation into future reserve and mine plan updates.

Drillhole 87-26-508 was planned with the same objective, targeting inferred material within the Z87 reserve pit and testing for additional hangingwall mineralization. The hangingwall returned an intercept of 0.43 g/t AuEq over 42 metres from an area of the block model that is not currently mineralized (Figure 3). The hole also returned 1.10 g/t AuEq over 96 metres from the main zone of Z87, which includes 2.59 g/t AuEq over 13.7 metres and 1.88 g/t AuEq over 16.5 metres.

Drillhole 87-26-481 successfully targeted inferred material directly under the previously mined pit (Figure 4). The hole returned 83 metres grading 0.55 g/t AuEq, including 1.10 g/t AuEq over 20 metres from the primary target, while the hangingwall returned 5.94 g/t AuEq over 1 metre and 1.78 g/t AuEq over 1 metres from areas of sparse mineralization in the current block model.

The holes included in this news release account for approximately 15% of the total metres expected to be drilled in and around the Z87 reserve pit as part of the ongoing optimization program.

Table 1. Z87 Drill Results

* AuEq = Au grade + 1.5628 * Cu grade + 0.0128 * Ag grade

Quality Assurance and Control

During the drill program, one meter assay samples were taken from NQ core and sawed in half. One-half was sent for assaying at ALS Laboratory in Sudbury Ontario, a certified commercial laboratory, and the other half was retained for results, cross checks, and future reference. A strict QA/QC program was applied to all samples; which included insertion of one certified mineralized standard and one blank sample in each batch of 25 samples. Every sample was processed with standard crushing to 85% passing 75 microns on 500 g splits. Samples were assayed by one-AT (30 g) fire assay with an AA finish and if results were higher than 3.5 g/t Au, assays were redone with a gravimetric finish. For QA/QC samples, a 50 g fire assay was done. In addition to gold, ALS laboratory carried out multi-element analysis for ME-ICP61 analysis of 33 elements four acid ICP-AES.

Qualified Person

The technical and scientific information in this press release has been reviewed and approved by Nicolas Guest, P.Geo., Exploration Manager, who is a Qualified Person as defined by NI 43-101. Mr. Guest is an employee of Troilus and is not independent of the Company under NI 43-101.

AuEq Disclosure

The formulas used to calculate equivalent values for resources are as follows, for 87 Pit AuEq = Au + 1.5628*Cu +0.0128 *Ag, for J Pit AuEq = Au + 1.5107*Cu +0.0119 *Ag, for SW Pit AuEq = Au + 1.6823*Cu +0.0124 *Ag, for X22 Pit AuEq = Au + 1.5628*Cu +0.0128 *Ag. AuEq was calculated using metal prices of $1,850/oz Au; $4.25/lb Cu and $23.00/oz Ag and recoveries of 93.1% for Au, 88.9% for Ag and 89.3% for Cu in the J pit, 95.5% for Au, 98.2% for Ag and 94.7% for Cu in the 87 pit, 85.7% for Au, 85.6% for Ag and 91.5% for Cu in the SW pit and 95.5 % for Au, 98.2% for Ag and 94.7% for Cu in the X22 pit.

About Troilus Mining Corp.

Troilus Mining Corp. is a Canadian development-stage mining company focused on the systematic advancement of the former gold and copper Troilus Mine towards production. Troilus is located in the tier-one mining jurisdiction of Quebec, Canada, where it holds a large land position of 435 km² in the Frôtet-Evans Greenstone Belt. A Feasibility Study completed in May 2024 supports a large-scale 22-year, 50ktpd open-pit mining operation, positioning it as a cornerstone project in North America.

For more information:

Caroline Arsenault
VP Corporate Communications
+1 (647) 276-0050
info@troilusmining.com  

Cautionary Note Regarding Forward-Looking Statements and Information

This press release contains “forward-looking statements” within the meaning of applicable Canadian securities legislation. Forward-looking statements include, but are not limited to, statements regarding the impact of the drill results on the Company, opportunity to expand the scale of the project, the project becoming a cornerstone mining project in Noth America; the development potential and timetable of the project; the estimation of mineral resources and reserves; realization of mineral resource and reserve estimates; the timing and amount of estimated future exploration; costs of future activities; capital and operating expenditures; success of exploration activities; the anticipated ability of investors to continue benefiting from the Company’s low discovery costs, technical expertise and support from local communities, the timing and amount of estimated future exploration; and the anticipated results of the Company’s 2026 drill program and their possible impact on the potential size of the mineral resource estimate. Generally, forward-looking statements can be identified by the use of forward-looking terminology such as “plans”, “expects” or “does not expect”, “is expected”, “budget”, “scheduled”, “estimates”, “forecasts”, “intends”, “continue”, “anticipates” or “does not anticipate”, or “believes”, or variations of such words and phrases or statements that certain actions, events or results “may”, “could”, “would”, “will”, “might” or “will be taken”, “occur” or “be achieved”. Forward-looking statements are made based upon certain assumptions and other important facts that, if untrue, could cause the actual results, performances or achievements of Troilus to be materially different from future results, performances or achievements expressed or implied by such statements. Such statements and information are based on numerous assumptions regarding present and future business strategies and the environment in which Troilus will operate in the future. Certain important factors that could cause actual results, performances or achievements to differ materially from those in the forward-looking statements include, amongst others, currency fluctuations, the global economic climate, dilution, share price volatility and competition. Forward-looking statements are subject to known and unknown risks, uncertainties and other important factors that may cause the actual results, level of activity, performance or achievements of Troilus to be materially different from those expressed or implied by such forward-looking statements, including but not limited to: there being no assurance that the exploration program or programs of the Company will result in expanded mineral resources or reserves; risks and uncertainties inherent to mineral resource and reserve estimates; the high degree of uncertainties inherent to feasibility studies and other mining and economic studies which are based to a significant extent on various assumptions; variations in gold prices and other metals, exchange rate fluctuations; variations in cost of supplies and labour; receipt of necessary approvals; availability of financing for project development; uncertainties and risks with respect to developing mining projects; general business, economic, competitive, political and social uncertainties; future gold and other metal prices; accidents, labour disputes and shortages; environmental and other risks of the mining industry, including without limitation, risks and uncertainties discussed in the Company’s latest Annual Information Form, its technical reports and other continuous disclosure documents of the Company available under the Company’s profile at www.sedarplus.ca. Although Troilus has attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking statements, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that such statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements. Troilus does not undertake to update any forward-looking statements, except in accordance with applicable securities laws.

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