Bullion Gold Discoveries Corp. press release

Challenger Underground MRE Doubles to 230koz @ 3.65 g/t Au

2026-10-28

TSXV - TSX Venture Exchange · Gold · Silver · Lithium · Copper · Zinc · Nickel · Cobalt · Lead · Rare Earth Elements · Molybdenum · Indium · Canada · Resource Estimate

##

'Hub 1' Resources at Challenger & Tarcoola grow to total 400koz Au

HIGHLIGHTS

Challenger underground surprises with 230koz Au on existing mine development; significant growth potential indicated with expedited review of development options to commence Total Challenger JORC (2012) Mineral Resources Estimate (MRE) grows to 370koz Au (11.2Mt @ 1.03 g/t), incl. 246koz Au (2.17Mt @ 3.53 g/t) in existing open pit and underground areas: Challenger Main Open Pit: 13,900oz Au (0.20Mt @ 2.16 g/t Au); Challenger West Open pit: 2,400oz Au (0.01Mt @ 6.09 g/t Au); Challenger Underground (above 215mRL): 206,800oz Au (1.75Mt @ 3.68 g/t Au); and Challenger Deeps (below 90mRL): 23,000oz Au (0.21Mt @ 3.50 g/t Au).

Existing Tarcoola stockpiles MRE (220Kt @ 1.23 g/t Au) upgraded to JORC 'Indicated' category Total 169koz Au open pittable 'Hub 1' Resources, including 62koz Au (1.41Mt @ 1.37 g/t) fresh mineralisation (52% Indicated) and 56koz Au (3.19Mt @ 0.54 g/t Au) in TSF1 (100% Indicated) Almost all MRE mineralisation located in, on, or adjacent to, existing serviceable open pit and underground development à opportunities for relatively low-cost access and production Includes new 'Challenger 3' Deposit confirmed along strike of Challenger ‘West' and ‘Main' pits; review indicates significant near-term growth potential for open-pittable 'baseload' mineralisation Definitive Feasibility Study (DFS) underway to evaluate capital and operating costs for potential Challenger operations restart leveraging existing, fully-permitted Central Gawler Mill (CGM)1

ADELAIDE, AU / ACCESS Newswire/ October 27, 2026 / Barton Gold Holdings Limited (ASX:BGD)(FRA:BGD3)(OTC PINK:BGDFF) (Bartonor Company) is pleased to announce updated MREs for each of its South Australian Challenger (Challenger) and Tarcoola (Tarcoola) Gold Projects.

Commenting on the Challenger & Tarcoola Resources update, Barton MD Alexander Scanlon said:

"Detailed remodelling of the Challenger high-grade underground has surprised to the upside, with Resources more than doubling to 230koz @ 3.65 g/t Au. This mine has extensive existing development and produced over 1 million gold ounces from 2002 to 2018. Third party review indicates significant growth potential through near-mine drilling.

"Barton is steadily building its platform, with Challenger and Tarcoola JORC Resources now totalling 400,000oz Au. This mineralisation has also now been modelled on a more conservative basis and constrained to optimised pit shells, increasing the potential for these materials to support a future ‘Hub 1' operation based at our Challenger project site.

"Our fully permitted Central Gawler Mill offers considerable infrastructure leverage with a potentially shorter, lower-cost, and lower-risk pathway to operations.Reanimation of the mill would also materially enhance the development optionality of our adjacent Challenger underground mine, and our regional assets Tarcoola, Tolmer, and Wudinna."

1Refer to Prospectus dated 14 May 2021

Updated Challenger JORC (2012) MRE

The new Challenger MRE reflects the original open pit (Challenger Main), the ‘West' open pit (Challenger West), the 'SSW' Deposit (CSSW), historical Tailings Storage Facilities 1 and 2 (TSF1and TSF2, respectively) the historical Challenger underground mine (UG), and a newly defined Challenger 3 Deposit (Challenger 3 orC3).2

All mineralisation is adjacent to the Company's Central Gawler Mill (CGM). The updated MRE excludes various lower-grade stockpiles and higher-grade mill residuals (eg. ball mill rejects) which are located adjacent to the CGM on the Run of Mine (ROM) pad. These materials will likely also form a component of early mill feed as the hard rock crushing and grinding circuits are recommissioned for the start of fresh rock processing operations.

[](https://app.accessnewswire.com/imagelibrary/e31e01fc-0176-456f-8554-5687bdd6d0a8/1243024/figure-1-challenger.png)

Figure 1 - Challenger site map with locations of key infrastructure and JORC (2012) MRE deposits

2Refer to Prospectus dated 14 May 2021

Comparison with prior Challenger JORC (2012) MRE

Challenger's updated JORC (2012) MRE (see Table 1 below) is based upon the integration of 9,387m new reverse circulation (RC) and diamond (DD) drilling results.3Key modelling updates and outcomes include:

the confirmation of a new open-pittable 'Challenger 3' Deposit along strike of the existing open pits; remodelling of ‘open pittable' Resources on a more conservative basis by constraining mineralisation to optimised open pit shells with revenue factors from 1.2 to 1.5 (base gold price of AUD $5,000 / oz); remodelling of underground mineralisation following further on-site review by third party consultants, including some mineralisation previously modelled as Challenger 'Main' open pit JORC Resources.

In particular, underground mineralisation has surprised to the upside with significant mineralisation added into the block model and Resources more than doubling to 230koz @ 3.65 g/t Au. A material grade improvement has also been observed where mineralisation previously modelled as 'open pit' Resources has been reclassified to 'underground' Resources with a view to more efficient and selective extraction.

Preliminary modelling by SRK Consulting Pty Ltd (SRK) has also indicated potential to bring significant additional high-grade mineralisation into a future MRE or mine plan through further near-mine drilling. An expedited review of potential underground development options is expected to commence shortly.

Additionally, a new 'Challenger 3' Deposit has been defined along strike of the CSSW Deposit and the existing Challenger 'West' and 'Main' open pits. Review indicates potential for additional growth through infill drilling (conversion of unclassified mineralisation) and growth / extensional drilling along strike of the new MRE.

| Zone | Measured | Indicated | Inferred | TOTAL | | | | | | | | | | | Mt | g/t Au | Koz Au | Mt | g/t Au | Koz Au | Mt | g/t Au | Koz Au | Mt | g/t Au | Koz Au | | Challenger Underground (above 215mRL) | -- | -- | -- | 0.11 | 4.82 | 17 | 1.64 | 3.60 | 190 | 1.75 | 3.68 | 207 | | Challenger Deeps

(below 90mRL) | -- | -- | -- | -- | -- | -- | 0.21 | 3.50 | 23 | 0.21 | 3.50 | 23 | | Challenger Main Open Pit | -- | -- | -- | 0.15 | 2.23 | 10 | 0.05 | 1.94 | 3 | 0.20 | 2.15 | 14 | | Challenger West Open Pit | -- | -- | -- | 0.01 | 6.66 | 2 | 0.00 | 3.3 | 0.2 | 0.01 | 6.1 | 2 | | Challenger SSW Deposit | -- | -- | -- | 0.18 | 0.86 | 5 | 0.20 | 0.69 | 4 | 0.38 | 0.77 | 9 | | Challenger 3 Deposit | -- | -- | -- | 0.21 | 0.89 | 6 | 0.07 | 0.68 | 1.63 | 0.29 | 0.84 | 8 | | Tailings Storage Facility 1 | -- | -- | -- | 3.19 | 0.54 | 56 | -- | -- | -- | 3.19 | 0.54 | 56 | | Tailings Storage Facility 2 | -- | -- | -- | 5.13 | 0.31 | 52 | -- | -- | -- | 5.13 | 0.31 | 52 | | TOTAL | -- | -- | -- | 8.98 | 0.51 | 148 | 2.17 | 3.18 | 222 | 11.2 | 1.03 | 370 | | * Totals subject to rounding; tonnages are dry metric tonnes; all Mineral Resources classified as 'Inferred' are approximate; cut-off grades applied are 2.0 (Deeps) 1.0 g/t Au (UG above 215 mRL), 0.3 g/t Au (Main Open Pit, Challenger West, SSW, Challenger 3) and 0.0 g/t Au (TSF1 and TSF2). | | | | | | | | | | | | |

Table 1 - Challenger JORC (2012) Mineral Resources Estimate (October 2026)

The prior Challenger JORC (2012) MRE, reported on 8 September 2025, was:4

| Zone | Measured | Indicated | Inferred | TOTAL | | | | | | | | | | | Mt | g/t Au | Koz Au | Mt | g/t Au | Koz Au | Mt | g/t Au | Koz Au | Mt | g/t Au | Koz Au | | Challenger Underground (above 215mRL) | -- | -- | -- | -- | -- | -- | 0.98 | 2.84 | 89.4 | 0.98 | 2.84 | 89.4 | | Challenger Deeps

(below 90mRL) | -- | -- | -- | -- | -- | -- | 0.21 | 3.50 | 23.0 | 0.21 | 3.50 | 23.0 | | Challenger Main Open Pit | -- | -- | -- | 0.17 | 2.69 | 14.8 | 0.48 | 3.61 | 55.2 | 0.65 | 3.36 | 70.0 | | Challenger West Open Pit | -- | -- | -- | -- | -- | -- | 0.03 | 10.7 | 11.6 | 0.03 | 10.7 | 11.6 | | Challenger SSW Deposit | -- | -- | -- | -- | -- | -- | 0.40 | 0.95 | 12.2 | 0.40 | 0.95 | 12.2 | | Challenger 3 Deposit | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | | Tailings Storage Facility 1 | -- | -- | -- | 3.19 | 0.54 | 55.5 | -- | -- | -- | 3.19 | 0.54 | 55.5 | | Tailings Storage Facility 2 | -- | -- | -- | 5.13 | 0.31 | 51.8 | -- | -- | -- | 5.13 | 0.31 | 51.8 | | TOTAL | -- | -- | -- | 8.49 | 0.45 | 122 | 2.09 | 2.84 | 191 | 10.6 | 0.92 | 313 | | * Totals subject to rounding; tonnages are dry metric tonnes; all Mineral Resources classified as ‘Inferred' are approximate; cut-off grades applied are 2.0 (Deeps) 1.0 g/t Au (UG above 215 mRL), 0.5 g/t Au (Main Open Pit, Challenger West, SSW) and 0.0 g/t Au (TSF1 and TSF2). | | | | | | | | | | | | |

Table 2 - Challenger JORC (2012) Mineral Resources Estimate (September 2025)4

3Refer to ASX announcement dated 16 April 2026 4 Refer to ASX announcement dated 8 September 2025

Updated Tarcoola JORC (2012) MRE

During July 2024 Barton announced an updated Tarcoola MRE of 30koz Au (0.54Mt @ 1.70 g/t Au), with ~44% classified as JORC 'Indicated' category.5Following remodelling, the Tarcoola MRE is now slightly revised to 29koz Au (0.53Mt @ 1.68 g/t Au), where the primary change is that ~72% is now classified as JORC ‘Indicated' category.

Comparison with prior Tarcoola JORC (2012) MRE

Tarcoola's updated JORC (2012) MRE (see Table 3 below) is based upon further review and validation of historical production records, and remodelling of stockpiled mineralisation for revised density assumptions. The stockpiled mineralisation has been reclassified from JORC ‘Inferred' category to JORC ‘Indicated' category.

| Zone | Measured | Indicated | Inferred | TOTAL | | | | | | | | | | | Mt | g/t Au | Koz Au | Mt | g/t Au | Koz Au | Mt | g/t Au | Koz Au | Mt | g/t Au | Koz Au | | Perseverance Open Pit | | | | | | | | | | | | | | Oxide | -- | -- | -- | -- | -- | -- | 0.00 | 0.62 | -- | 0.00 | 0.62 | 0 | | Transitional | -- | -- | -- | 0.01 | 1.34 | 0 | 0.01 | 1.00 | 0 | 0.01 | 1.14 | 1 | | Fresh | -- | -- | -- | 0.18 | 2.12 | 12 | 0.11 | 1.89 | 7 | 0.30 | 2.03 | 19 | | Subtotal | -- | -- | -- | 0.19 | 2.10 | 13 | 0.12 | 1.82 | 7 | 0.31 | 1.99 | 20 | | Stockpiles | | | | | | | | | | | | | | Oxide | -- | -- | -- | 0.16 | 1.20 | 6 | -- | -- | -- | 0.16 | 1.20 | 6 | | Fresh | -- | -- | -- | 0.05 | 1.40 | 2 | -- | -- | -- | 0.05 | 1.40 | 2 | | Subtotal | -- | -- | -- | 0.22 | 1.23 | 9 | -- | -- | -- | 0.22 | 1.23 | 9 | | TOTAL | -- | -- | -- | 0.41 | 1.63 | 21 | 0.12 | 1.82 | 7 | 0.53 | 1.68 | 29 | | * Totals subject to rounding; tonnages are dry metric tonnes; cut-off grades applied are 0.5 g/t Au (Perseverance Pit) and 0.4 g/t Au (stockpiles). | | | | | | | | | | | | |

Table 3 - Tarcoola JORC (2012) Mineral Resources Estimate (October 2026)

The prior Tarcoola JORC (2012) MRE, reported on 3 July 2024, was:5

| Zone | Measured | Indicated | Inferred | TOTAL | | | | | | | | | | | Mt | g/t Au | Koz Au | Mt | g/t Au | Koz Au | Mt | g/t Au | Koz Au | Mt | g/t Au | Koz Au | | Perseverance Open Pit | | | | | | | | | | | | | | Oxide | -- | -- | -- | -- | -- | -- | 0.00 | 0.62 | -- | 0.00 | 0.62 | 0 | | Transitional | -- | -- | -- | 0.01 | 1.34 | 0 | 0.01 | 1.00 | 0 | 0.01 | 1.14 | 1 | | Fresh | -- | -- | -- | 0.18 | 2.12 | 12 | 0.11 | 1.89 | 7 | 0.30 | 2.03 | 19 | | Subtotal | -- | -- | -- | 0.19 | 2.10 | 13 | 0.12 | 1.83 | 7 | 0.31 | 1.99 | 20 | | Stockpiles | | | | | | | | | | | | | | Oxide | -- | -- | -- | -- | -- | -- | 0.17 | 1.20 | 7 | 0.17 | 1.20 | 7 | | Fresh | -- | -- | -- | -- | -- | -- | 0.06 | 1.40 | 3 | 0.06 | 1.40 | 3 | | Subtotal | -- | -- | -- | -- | -- | -- | 0.23 | 1.30 | 10 | 0.23 | 1.30 | 10 | | TOTAL | -- | -- | -- | 0.19 | 2.10 | 13 | 0.35 | 1.48 | 17 | 0.54 | 1.70 | 30 | | * Totals subject to rounding; tonnages are dry metric tonnes; cut-off grades applied are 0.5 g/t Au (Perseverance Pit) and 0.4 g/t Au (stockpiles). | | | | | | | | | | | | |

Table 4 - Tarcoola JORC (2012) Mineral Resources Estimate (July 2024)5

5Refer to ASX release dated 3 July 2024

Challenger Definitive Feasibility Study

A DFS is underway targeting an initial 3 - 4 year Stage 1 'baseline' operation utilising only historical higher-grade tailings from tailings storage facility 1 (TSF1)and limited, near-surface materials without disturbing Challenger's historical high-grade underground mine, its mineralisation or its infrastructure access.

In support of the DFS, Barton has now completed the following programs of work, among others:6

a detailed condition assessment of the Central Gawler Mill (CGM) and supporting infrastructure; TSF1 geotechnical and metallurgical drilling, and comminution and metallurgical testwork;7 a further 8,065m RC and 1,322 DD drilling;8and preliminary capital and operating cost estimates (subject to scale and throughput scenario analysis).

These analyses support the conclusions that the CGM is suitable for recommissioning to operations, and that TSF1 materials reprocessing is considered technically feasible and operationally practical.9

The CGM offers a material leverage point for Barton to commence de-risked ‘Hub 1' operations, and also materially enhances the development optionality of Barton's regional assets including Tarcoola Gold Project (Tarcoola), Wudinna Gold Project (Wudinna) and high-grade Tolmer silver prospect (Tolmer).

All of these potential sources of mineralisation could potentially be processed through the CGM.

Follow-up analysis and drilling

Barton is continuing its analysis of potential optimal startup and development pathways for the CGM, with a preference for pathways that reduce risk. Barton is targeting DFS publication during Q1 CY27.

Remodelling of Challenger's underground Resources, along with preliminary modelling of the underground's other unclassified mineralisation by SRK, has also raised interesting questions about the potentially greater prospects for further Resources growth, and also for integrating this mineralisation into development plans. Barton expects to shortly commence an expedited review of potential underground development options.

Finally, review of recent drilling and updated modelling of mineralisation has identified multiple targets for potential follow-up drilling, including:

further infill and extension of the new Challenger 3 Deposit, and infill of Challenger SSW, to convert low-risk, open pittable mineralisation into JORC ‘Indicated' category as potential ‘baseline' mill feed; further infill and extension of drilling on the Challenger 'Main' open pit, where the latest drilling has recently confirmed new zones of high-grade mineralisation up to 170 g/t Au in the pit walls;10and drilling of Challenger's underground targeting material volumes of mineralisation for conversion to JORC Resources classification.

The Company will provide further updates in due course.

6Refer to ASX announcement dated 14 May 2026 7Refer to ASX announcements dated 30 June and 8 / 29 September 2025 8Refer to ASX announcement dated 16 April 2026 9Refer to ASX announcement dated 14 May 2026 10Refer to ASX announcement dated 20 April 2026

Updated Company JORC Mineral Resources Statement

Further to the updated MRE detailed in this announcement:*

Barton's total JORC (2012) Mineral Resources gold endowment is now 2.29Moz (80.4Mt @ 0.89 g/t Au); and Barton's total JORC (2012) Mineral Resources silver endowment is now 3.1Moz (34.5Mt @ 2.80 g/t Au).

[](https://app.accessnewswire.com/imagelibrary/f3b68c5b-6f94-4cc8-85da-66a4e15a1584/1243024/picture2.jpg)

[](https://app.accessnewswire.com/imagelibrary/f5b65303-0ad8-427a-a1f3-0185ce7a5bcb/1243024/table.jpg)

Tables show the complete JORC MRE for each Project. Figures are subject to rounding, tonnages are dry-metric tonnes, and all Mineral Resources classified as ‘Inferred' are approximate.

Gold cut-off grades applied are:

Tunkillia

0.3 g/t Au (Area 223) 0.3 g/t Au (Area 51)

Tarcoola

0.5 g/t Au (Perseverance Pit) 0.4 g/t Au (Stockpiles)

Challenger

0.3 g/t Au (Main, West, SSW, C3) 1.0 g/t Au (Main UG, West UG) 2.0 g/t Au (Deeps) 0.0 g/t Au (TSF1 & TSF2)

Wudinna

0.5 g/t Au (all Deposits)

Silver is considered as a by-product and is reported as a subset of the reported gold MRE, and has only been reported where the block model reports >0.3g/t Au.

Silver resources are reported only as Inferred resources independent of the block model classification for gold. Mineral Resources are reported using a gold price of A$3,500 / ounce.

Refer to Prospectus and ASX announcements dated 14 Oct 2021, 26 Apr 2023, 1 Sep 2023, 11 Dec 2023, 4 Mar 2024, 3 Jul 2024, and 4 Mar / 30 Jun / 2 Jul / 8 Sep 2025 and 28 October 2026 for further details of JORC (2012) Mineral Resource Estimates and Barton's JORC (2012) Mineral Resources inventory.

Figure 2 - Barton updated JORC Gold & Silver Mineral Resources Estimates (October 2026)*

2026 Mineral Resource Estimate for the Challenger Project (above 215 Fault, ~215 m RL) and the Tarcoola Project, South Australia.

1. Summary

The Challenger gold deposit, mined as an open pit and underground operation between 2002 and 2018 and producing ~1.2 Moz gold, is located in the Gawler Craton, South Australia. It is ~730 km northwest of Adelaide, South Australia and ~130 km northwest of Tarcoola, South Australia. The Project is owned by Barton Gold Holdings Ltd (BGD) and comprises the Challenger Mine, ~650 ktpa mill/processing plant ("Central Gawler Mill"), mine camp and associated infrastructure. The Challenger gold deposit was discovered in 1995 by Dominion Mining.

The deposit is hosted within high-grade metamorphic rocks and is characterised by structurally controlled quartz veins.

The resource (Table 1) is reported within optimised pit shells and above a 0.3 g/t gold cut off, below the pit shells and above the modelled 215 Fault (~215 mRL) the resource is reported above a 1.0 g/t cut off.

Table 1. Challenger Mineral Resource Estimate 2026

| Cut off | Resource | Area | Tonnes | Grade (Au g/t) | Gold (koz) | | > 0.3 g/t | Indicated | M lodes | 50,000 | 1.98 | 3.20 | | | | SEZ lodes | 96,000 | 2.36 | 7.28 | | | | W lodes | 10,000 | 6.66 | 2.11 | | | | SW lodes | 182,000 | 0.86 | 5.05 | | | | CH3 lode | 212,000 | 0.89 | 6.07 | | > 0.3 g/t | Inferred | M lodes | 50,000 | 1.98 | 3.20 | | | | SEZ lodes | 4,000 | 1.40 | 0.18 | | | | W lodes | 2,000 | 3.33 | 0.24 | | | | SW lodes | 198,000 | 0.69 | 4.39 | | | | CH3 lode | 74,000 | 0.68 | 1.63 | | > 1.0 g/t | Indicated | M lodes | 98,000 | 3.99 | 12.6 | | | | SEZ lodes | 6,000 | 2.69 | 0.52 | | | | W lodes | 7,000 | 19.1 | 4.02 | | > 1.0 g/t | Inferred | M lodes | 1,120,000 | 3.93 | 141.4 | | | | SEZ lodes | 430,000 | 2.24 | 30.86 | | | | W lodes | 88,000 | 6.12 | 17.39 | | Total | | | 2,627,000 | 2.84 | 240.1 |

Due to rounding to appropriate significant figures, minor discrepancies may occur, tonnages are dry metric tonnes. Mineral Resources are not Ore Reserves and do not have demonstrated economic viability.

Inferred resource have less geological confidence than Indicated resources and should not have modifying factors applied to them. It is reasonable to expect that with further exploration most of the inferred resources could be upgraded to indicated resources.

Significant exploration work has been undertaken to define new resources at the southwest (SW) lodes and Challenger 3 (CH3) deposits.

In addition to the above resources (Table 1) are two tailings storage facilities (TSF) on the Challenger leases and two stockpiles on the Tarcoola leases; An indicated mineral resource for the tailings storage facility is reported (no cut off, Table 2) as it is envisaged hydraulic mining (no selectivity) will be used.

Table 2. Challenger TSF Mineral Resource Estimate 2026

| Indicated Material | tonnes (t) | Grade (Au g/t) | Gold (koz) | | TSF1 | 3,190,000 | 0.54 | 55.5 | | TSF2 | 5,130,000 | 0.31 | 51.8 | | Total | 8,330,000 | 0.40 | 107.3 |

Due to rounding to appropriate significant figures, minor discrepancies may occur, tonnages are dry metric tonnes. Mineral Resources are not Ore Reserves and do not have demonstrated economic viability.