Mammoth Resources Corp. press release

Mithril Silver And Gold June 2026 Quarterly Report Upgraded T1 MRE And District Expansion Drill Program

2026-07-31

TSXV - TSX Venture Exchange · Gold · Silver · Copper · Canada · Resource Estimate

(TheNewswire)

| [](www.mithrilsilvergold.com) | | |

Melbourne, Australia and Vancouver, Canada – July 31, 2026 – TheNewswire -Mithril Silver and Gold Limited ("Mithril” or the "Company") (TSXV: MSG) (ASX: MTH) (OTCQB: MTIRF) is pleased to report on its quarterly activities and cash flow for its Copalquin and La Dura properties in Durango State, Mexico for the period ended June 30, 2026.

EXPLORATION HIGHLIGHTS

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Significant mineral resource estimate (MRE) upgrade with total constrained and dilutedIndicated and Inferred resources of 343 koz gold + 8.479 Moz silver(464 koz AuEq) and 103 koz gold + 3.398 Moz silver (151 koz AuEq),respectively. Indicated totals 3.391 Mt grading 3.15 g/t gold and 77.8 g/t silver (diluted) and Inferred totals 1.436 Mt grading 2.23 g/t gold and 73.6 g/t silver (diluted). See Table 2 for details1

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196% increase in higher-confidence indicated gold and silvercompared to previous MRE.

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75% of total gold and silver now classified as indicated

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Resource constrained within preliminary underground mining shapes and incorporates expected mining dilution, providing a more realistic basis for future engineering and economic studies

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High confidence resource, remains open along strike and at depth with multiple opportunities for expansion

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Overall Target 1 MRE discovery cost of less than US$20 per ounce AuEqfrom approximately 60,000 metres of drilling in 204 drill holes

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First drilling at Target 3 areasince 2020 has shown extensive gold and silver mineralisation with high grades intercepted. Further drilling planned for next quarter.

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Drilling at Target 5 has expandedthe known gold-silver mineralisation with high grades intercepted at the La Maquina area

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The final Target 1 drilling for the for the MRE upgrade produced strong results on the western end of the deposit area for extensional follow-up.

Corporate

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Cash balance of A$7.3M as of 30 June 2026 and Mithril remains debt free

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Mexican value added tax refunds have continued with MXN11.5M (~A$940k) of refunds received in Mexico during the June 2026 quarter.

Commenting on the June 2026 quarter, Managing Director and CEO John Skeet said:

“The June quarter marked a significant step in the systematic de-risking of Target 1 and the broader expansion of the large Copalquin epithermal silver-gold system. The upgraded MRE moves the deposit beyond a purely geological inventory by constraining the resource within preliminary underground mining shapes and incorporating dilution. This provides a more practical foundation for mine planning, engineering and economic evaluation.

The Target 1 drilling program strengthened the geological model at El Refugio and La Soledad. Results confirmed continuity through and beyond the post-mineral dyke system, identified additional mineralised structures and demonstrated that the system remains open. The knowledge gained at Target 1 is being applied across the broader Copalquin district.

Two drills are active on site to execute the remaining fully funded 12,000 metres of drilling for the 2026 program. The aim of the program is to advance other current target areas for additional resources and to test the deeper system driving targets identified from the extensive mapping, geophysics and structural work across this exceptional epithermal system.”

PLANNED EXPLORATION ACTIVITIES – SEPTEMBER 2026 QUARTER

During the September 2026 quarter, Mithril plans to:

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Drill test west and northwest of the Target 1 resource area

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Follow-up drilling along strike from the high-grade intercepts at the historic Copalquin mine workings

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Progress a series of deep, key structural targeting drill holes across the district

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Follow-up drilling to test deeper at Target 3

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Progress economic assessment and derisking work for the Target 1 resource area

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Progress initial drill plan and permitting for La Dura

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Fully funded to complete remaining 12,000 m of drilling for 2026

TARGET 1 MRE UPGRADE

(For full detail of the Target 1 MRE Upgrade see ASX announcement 3 July 2026 – “Amended Announcement Copalquin Project Target 1 Deposit MRE”)

The following Table 1provides the highlighted base case for undiluted mineralisation reporting within the underground mining shapes (mine stope optimiser – MSO) at a cut-off grade of 1.5 g/t AuEq plus sensitivities to gold prices.

The MRE for Target 1(Table 2) was generated from the highlighted base case in Table 1assuming bulk underground mining method (long hole open stoping - LHOS) with mining widths averaging approximately 4 metres as presented on a diluted basis in Table 2. The MSO work identified areas where more selective underground mining methods such as cut and fill (higher cost than LHOS) could be utilised to reduce dilution and increase mined grades.The difference between the undiluted grade of 6.85 g/t AuEq ([]()Table 1Indicated base case) and the diluted grade of 4.26 g/t AuEq (Table 2, TotalIndicate Target 1 MRE) reflects this conservative mining dilution assumption whereby lower grade mineralisation surrounding the high-grade core would be extracted within geometry of a minable shape adding more tonnes and ounces at a lower average grade.More detailed mining study work will fully assess the mining methods across the Target 1 MRE.

Table []()1Gold price sensitivity to constraining shapes, reported at 1.5 g/t AuEq cut-off (constrained and undiluted)

| Au Prices | Classification | Tonnes | Gold | Silver | Gold Eq. | Gold | Silver | Gold Eq. | | (USD) | | (kt) | (g/t) | (g/t) | (g/t) | (koz) | (koz) | (koz) | | 2,700 | Ind | 1,888 | 5.28 | 126.1 | 7.08 | 321 | 7,654 | 430 | | Inf | 831 | 3.46 | 113.7 | 5.08 | 92 | 3,038 | 136 | | | 3,000 | Ind | 1,941 | 5.18 | 124.2 | 6.96 | 323 | 7,752 | 434 | | Inf | 863 | 3.39 | 111.7 | 4.98 | 94 | 3,099 | 138 | | | 3,300 | Ind | 1,990 | 5.10 | 122.4 | 6.85 | 326 | 7,832 | 438 | | Inf | 900 | 3.32 | 109.1 | 4.87 | 96 | 3,155 | 141 | | | 3,500 | Ind | 2,038 | 5.01 | 120.9 | 6.74 | 329 | 7,922 | 442 | | Inf | 923 | 3.27 | 107.5 | 4.81 | 97 | 3,189 | 143 | | | 4,000 | Ind | 2,074 | 4.96 | 119.7 | 6.67 | 330 | 7,984 | 445 | | Inf | 949 | 3.23 | 105.9 | 4.74 | 98 | 3,233 | 145 | |

Notes to Table 1:

1.

The Table presents the results of a sensitivity analysis by varying gold prices on AuEq block model values and reports an undiluted tonnage, grade and metal content contained within the mining shapes. The scenarios as presented are not considered to be a statement of mineral resources or reserves, and do not have demonstrated economic viability.

2.

AuEq calculated using metal prices of USD $3,300/oz Au and $50/oz Ag where AuEq g/t = Au g/t + (Ag g/t x (Au price/Ag price) x (Ag recovery/Au recovery)) with metallurgical recoveries of 96% Au and 91% Ag from metallurgical test work on Target 1 composite samples 2. An AuEq cut-off grade of 1.5 g/t was selected after applying 95% mining recovery and 5% dilution factors to the metal price and metallurgical recovery values.

[]()

Table []()2Upgraded Copalquin Target 1 Mineral Resource Estimate (underground mining shape constrained & diluted)

| Target 1 Area | Class | Tonnes | Gold | Silver | Gold Eq. | Gold | Silver | Gold Eq. | | | | (kt) | (g/t) | (g/t) | (g/t) | (koz) | (koz) | (koz) | | El Refugio | Ind | 2,557 | 3.38 | 73.7 | 4.44 | 278 | 6,061 | 365 | | | Inf | 1,217 | 2.17 | 82.1 | 3.35 | 85 | 3,214 | 131 | | La Soledad | Ind | 834 | 2.43 | 90.2 | 3.72 | 65 | 2,418 | 100 | | | Inf | 219 | 2.54 | 26.1 | 2.92 | 18 | 184 | 21 | | Total | Ind | 3,391 | 3.15 | 77.8 | 4.26 | 343 | 8,479 | 464 | | | Inf | 1,436 | 2.23 | 73.6 | 3.28 | 103 | 3,398 | 151 |

Notes to Table 2:

1.

Numbers may not add due to rounding.

2.

All dollar values in United States Dollars (USD) unless otherwise noted.

3.

Mineral resources were prepared in accordance with the CIM Definition Standards (2014) and Estimation of Mineral Resource and Mineral Reserve Best Practice guidelines (2019), which are materially identical to the JORC Code (2012).

4.

The preparation of the mineral resource estimate was supervised by John Sims, President of Sims Resources LLC, an independent contractor and Qualified Person (QP), and Competent Person (CP), as a Certified Professional Geologist (CPG) member with the American Institute of Professional Geologists (AIPG).

5.

The effective date of the estimate is June 29, 2026.

6.

Inferred Mineral Resources have been estimated from geological evidence and drill core sampling and have a lower level of confidence than Measured and Indicated Mineral Resources due to the distance between sampled drill holes. Mineral resources are not mineral reserves and do not have demonstrated economic viability.

7.

Constrained and diluted Mineral Resources for Copalquin Target 1 are based on underlying metal prices of $3,300/oz Au and $50/oz Ag, unless otherwise noted.

8.

AuEq g/t = Au g/t + (Ag g/t x (Au price/Ag price) x (Ag recovery/Au recovery)), and is calculated using the underlying metals prices, along with metallurgical recoveries of 96% Au and 91% Ag from metallurgical test work on Target 1 composite samples. 3

9.

Underground Resource estimates are based on economically constrained mining shapes generated using Datamine’s Mineable Shape Optimizer (MSO) algorithm and the following optimization parameters:

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Diluted to a minimum 2 m shape width with a 92% mining recovery.

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Metallurgical recoveries of 96% for Au and 91% for Ag, from metallurgical test work on Target 1 composite samples 2 Longhole Open Stope mining with a total Mining+Processing+General and Administration (GA) cost of $97/t processed operating cost comprised of $60/t incremental mining, $25/t processing, $10/t GA, and $2/t sustaining.

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The mineable shapes reported are valued greater than the incremental cost to mine, which equates to approximately 1.0 g/t AuEq on a fully diluted basis.

10.

Mineral resources may be materially affected by environmental, permitting, legal, title, taxation, sociopolitical, marketing, or other relevant issues.

11.

In the Company’s opinion there is reasonable potential for both gold and silver to be extracted and sold.

[]()Target 1 Resource Upgrade Details

The Copalquin Target 1 resource model was prepared under the supervision of Sims Resources LLC (Independent QP) in accordance the JORC Code (2012) and to be consistent with the CIM Definition Standards (2014) and Estimation of Mineral Resource and Mineral Reserve Best Practice guidelines (2019) which are materially identical to the JORC Code (2012).

The estimate incorporates results from 204 diamond drill holes totaling approximately 60,568 metres, including 127 drill holes totalling approximately 42,861 metres completed since the previous resource estimate. The recent drilling was primarily focused on:

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Increasing drill density within the core of the deposit to improve resource confidence;

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Extending known mineralised shoots along strike and down plunge;

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Testing interpreted extensions of high-grade structures; and

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Improving the geological model through enhanced structural understanding and dyke mapping.

The resource estimate has been prepared as a major de-risking milestone to serve as a valuable stepping stone towards future development of a mineable resource supported by an economic study. Application of the mine stope optimization process to constrain the block model by mining shapes has achieved several goals including the evaluation of realistic minimum mining widths on the deposit, evaluation of the continuity of the mineralisation along potential underground development levels and has provided understanding of a potential extractable grade that incorporates the mineralised dilution envelope surrounding the high-grade core of the deposit.

An evaluation of gold price sensitivity on the mining shape constraints, on a diluted basis indicates a narrow band of output scenarios across a wide range of metal prices (Table 3). Evaluating the sensitivity scenarios on an undiluted basis (Table 1) reveals the high-grade core of the deposit that is driving the mining shapes.

With 95% of the undiluted and high-grade core of the block model being captured by the mining shape constraints, there is opportunity to drill the remaining 5% of the block model to refine mineralisation boundaries for potential inclusion to future constrained mineral resource estimates.

[]()Table []()3Gold price sensitivity to constraining shapes, reported using all contained blocks (diluted)

| Au Price | Classification | Tonnes | Gold | Silver | Gold Eq. | Gold | Silver | Gold Eq. | | (USD) | | (kt) | (g/t) | (g/t) | (g/t) | (koz) | (koz) | (koz) | | 2,700 | Ind | 2,939 | 3.52 | 85.9 | 4.75 | 333 | 8,114 | 449 | | Inf | 1,187 | 2.53 | 83.4 | 3.72 | 97 | 3,183 | 142 | | | 3,000 | Ind | 3,130 | 3.35 | 82.3 | 4.53 | 338 | 8,283 | 456 | | Inf | 1,291 | 2.39 | 79.1 | 3.52 | 99 | 3,285 | 146 | | | 3,300* | Ind | 3,391 | 3.15 | 77.8 | 4.26 | 343 | 8,479 | 464 | | Inf | 1,436 | 2.23 | 73.6 | 3.28 | 103 | 3,398 | 151 | | | 3,500 | Ind | 3,718 | 2.92 | 72.9 | 3.96 | 349 | 8,711 | 474 | | Inf | 1,588 | 2.07 | 68.5 | 3.05 | 106 | 3,498 | 156 | | | 4,000 | Ind | 4,149 | 2.67 | 67.2 | 3.63 | 356 | 8,965 | 484 | | Inf | 1,815 | 1.88 | 62.4 | 2.77 | 110 | 3,640 | 162 | |

Notes to Table 3:

1.

AuEq g/t = Au g/t + (Ag g/t x (Au price/Ag price) x (Ag recovery/Au recovery)), and is calculated using the underlying metals prices, along with metallurgical recoveries of 96% Au and 91% Ag from metallurgical test work on Target 1 composite samples. 4

2.

MSO shapes were based on long hole stope configuration with a 2.0 m minimum width, and a USD $97/t operating cost comprised of $60/t incremental mining, $25/t processing, $10/t GA, and $2/t sustaining, and 92% mining recovery. Blocks were evaluated using AuEq value, using variable gold prices according to the sensitivity scenario.

3.

The scenarios as presented are not considered statement of mineral resources or reserves, and do not have demonstrated economic viability.

Reporting of Constrained and Diluted Mineral Resources, Mining and Processing Methods

Mineral Resources are reported from within economically constrained Longhole Open Stopes (LHOS) mining shapes generated using Datamine’s Mineable Shape Optimizer (MSO). An operating cost of $97/t processed operating cost comprised of $60/t incremental mining, $25/t processing, $10/t G&A, and $2/t sustainingwas applied. An AuEq grade was basis used to determine block value using (1) a gold price of US$3,300/oz; (2) a silver price of US$50/oz; (3) gold recovery of 96%; (4) silver recovery of 91%, based on preliminary studies. Reported gold and silver grades in the Mineral Resource are stope-constrained and include internal dilution. No external dilution was applied. Historical workings were flagged to the block model and were assigned a density of 0.0 t/m3 to exclude mined out material from the stated Mineral Resources.

LHOS parameters applied in stope optimization include the following – (1) sublevel spacing = 20m; (2) stope slice interval = 5m; (3) minimum mining width = 2m; (4) minimum stope dip = 45 degrees; (5) minimum pillar between adjacent stopes = 0.01m; (6) Indicated and Inferred assurance categories only.

Metallurgical recoveries of 96% Au and 91% Ag were determined from metallurgical test work on Target 1 composite samples.(ASX Announcement 25 February 2022). The process route for extraction is crushing and grinding followed by flotation, intensive cyanide leaching of flotation concentrate and conventional cyanide leaching of the flotation tail. Merrill-Crowe zinc precipitation assumed to recover gold and silver from solutions prior to smelting of the precipitate to produce gold-silver doré bars for sale.

[](https://www.thenewswire.com/data/tnw/clients/img/257843d4c092254d118d12845dc34590.png) Click Image To View Full Size

Figure []()1: Series of plan view maps of the Mineral Resource Estimate showing: a) AuEq grade (g/t), b) block classification, and c) mining shapes used to constrain the block model

[](https://www.thenewswire.com/data/tnw/clients/img/f9aee5803aa3ecf7a98c33a3dcebc158.png) Click Image To View Full Size

Figure []()2: Cross- section view of El Refugio, looking east, showing the mineralised block model and the mining shape constraints used in the Mineral Resource Estimate

[](https://www.thenewswire.com/data/tnw/clients/img/c3cc72c6d65a21f3d4318e9dbec51a2e.png) Click Image To View Full Size

Figure []()3: Cross- section view of La Soledad, looking northwest, showing the mineralised block model and the mining shape constraints used in the Mineral Resource Estimate

Target 3 – Initial 2026 Drill Program

Target 3, on the eastern side of the district, is hosted in a favourable intermediate volcaniclastic tuff and breccia with several phases of rhyolitic intrusive and flows present. Dominant veins are trending east-west, northwest and locally in a less common northeast trend at Jabali. Styles of mineralisation include disseminated and banded silver-sulphides, as well as observed visible gold(GU26-002).

These features indicate high level continuity within the broad property wide east-west mineral trend and/or a localized upwelling source to mineralisation. Intersection of the Jabali and Guadalupe structures is projected approximately 950 metres west of Guadalupe and approximately 200 metres south of the southernmost Jabali drillhole JA26-004 and is a favourable target for future drill testing. The Target 3 drill programs are described below, and drilling highlights are listed in Table 4.

The first programof shallow drilling in the Target 3area since 2020 has tested 700 metres of strike within this 1.2 km x 1.2 km area.

Target 3 Drill Program Highlights include:

0.90 m @ 2.79 g/t gold, 151 g/t silverfrom 151.0 m (JA26-002)

0.50 m @ 6.91 g/t gold, 475 g/t silver from 102.5 m (JA26-004)

0.50 m @ 33.2 g/t gold, 5.9 g/t silverfrom 134.95 m (GU26-002)

The drill program at Target 3, consisting of 3,039 m, tested four of several historic workings. These initial results confirm extensive epithermal style mineralisation, with important key attributes observed in the drill core. The vein style and grades being intercepted indicate the mineralisation is at a high level in the system, with best intercepts and vein thicknesses found deeper in the drill holes. The results establish Target 3 as a highly prospective area for growth, reinforcing the broader district scale upside at Copalquin.

Further drilling is planned for Target 3 in the second half of 2026.

Jabali

Six drill holes were completed at Jabali to test two veins mapped on surface and within historical workings. The Jabali main workings, located to the north, have less than 150 metres of lateral development over two levels, while the smaller southern workings have about 40 metres of lateral development on one level. Recent channel sampling in the Jabali main workings returned assay results of up to 0.65 m at 16 g/t gold and 1,275 g/t silver5. Drill results confirm vein continuity down dip and along strike at least 230 metres with mineralisation remaining open in all directions.

Guadalupe

Five holes were drilled at Guadalupe to test the dip of a small stope in historical workings. Hole GU26-002 intersected minor veining and stockwork with visible gold. Channel samples from quartz veining near historical workings on the surface returned assay results of up to 0.50 m at 13.25 g/t gold and 558 g/t silver6. These holes confirm the presence of quartz veining with epithermal breccia textures within a broad zone of anomalous gold and silver mineralisation.

Constancia

Two holes were drilled along the northwest trending Constancia veins. The first hole tested a small historical working approximately 150 metres immediately south of Jabali while the second drill hole tested the down dip continuity of mapped surface vein located 100 metres immediately south of the Guadalupe workings. Hole CS26-001 intersected weak alteration and anomalous gold and silver grades over 4 m, from approximately 177-181 m. CS26-002 intercepted weak to moderate alteration over 30 metres between 45-75 m with anomalous gold and silver grades.

El Maizon

Two holes were drilled to test the continuity of a new vein mapped on surface along an interpreted east-west mineral trend. The holes successfully intercepted quartz breccia/epithermal veining and anomalous gold and silver assays over several intervals within weakly altered microdiorite.