Black Horse Mining Mobilises Diamond Rig and Secures Sister Rose Adit Permit

Black Horse Mining mobilises diamond rig and secures adit permit at Mt Egerton

Black Horse Mining Ltd (ASX: BHL) has reported two operational developments at the Mount Egerton Gold Project in Victoria: mobilisation of a high-capacity UDR1200 diamond drill rig and receipt of a permit to re-establish the historic Sister Rose Adit. According to the ASX announcement dated 19 June 2026, the Black Horse Mining Mt Egerton drilling and Sister Rose Adit permit developments support an upcoming drill programme of approximately 4,000 metres across 10 holes and will provide access to historical underground workings on the Sister Rose and Rose gold lodes.

Both developments sit alongside the release of final assay results from the maiden drill programme, which included anomalous gold in drillholes 25MEDD002 and 26MEDS001.

Two operational catalysts at Mount Egerton

The announcement describes two immediate catalysts for the Mount Egerton Gold Project:

• UDR1200 diamond rig mobilised

  • High-capacity diamond rig mobilised to site.
  • Drilling is expected to commence within days of the announcement.
  • Planned programme: ~4,000 m across 10 holes.

• Permit granted to re-establish Sister Rose Adit

  • Permission received from the Department of Energy, Environment and Climate Action (DEECA) and Resources Victoria.
  • Refurbishment of the adit is expected to be completed within two months.
  • Once re-established, Black Horse Mining Ltd expects to access historical workings on the Sister Rose and Rose lodes and locate the Sister Rose shaft.

"We are excited to begin the next phase of drilling aimed at positioning the 3D geological model and then testing the deeper part of the deposit. I would also like to commend the various Victorian Government departments for the speed at which the work to re-establish the Sister Rose Adit was approved; this bodes well for further exploration and development activities at the Project," said David Frances, Managing Director & CEO, Black Horse Mining Ltd.

For investors tracking timing, the immediate and near-term project milestones can be summarised as follows:

Educational focus: what an adit is and why it matters

The Sister Rose Adit is central to the current field strategy at Mt Egerton. For investors without an underground mining background, understanding what an adit is and why it is relevant to targeting drill holes is, consequently, quite important.

What is an adit?

An adit is a horizontal or near-horizontal tunnel driven into a hillside to reach underground mine workings. It differs from a shaft, which is vertical or steeply inclined.

In practical terms:

• An adit:

  • Provides access for people and equipment.
  • Allows ore and waste rock to be transported along a relatively flat path.
  • Often connects surface facilities with underground workings at a certain level.

• A shaft:

  • Connects surface and underground vertically or near-vertically.
  • Is used for hoisting ore, personnel, or ventilation.

At Mt Egerton, the Sister Rose Adit was historically used to haul ore from the one-level of the Sister Rose mine to the surface stamp battery, as depicted in historical imagery referenced in the announcement.

Role of the Sister Rose Adit at Mt Egerton

According to Black Horse Mining Ltd, once the adit is re-established:

• The location of the Sister Rose shaft should be determined.
• The 3D model of the underground workings can be accurately positioned.
• Access to historical workings on the Sister Rose and Rose lodes will be possible.

This matters operationally because underground access provides direct observation of rock types, quartz reef orientations, and structures controlling gold mineralisation. Furthermore, these observations can improve the accuracy of the 3D geological model, the placement and orientation of follow-up drill holes, and the interpretation of historical mining data relative to new drilling.

For investors, this type of underground reference point can reduce uncertainty around where drilling is focused, particularly when the objective is to test extensions of known lodes or deeper parts of the system.

Key technical terms explained

Maiden drill programme: final results and context

The announcement also reports final assay results from the maiden diamond drill programme at Mt Egerton. This programme formed part of the first phase of modern drilling by Black Horse Mining Ltd at the project.

Programme overview

According to the Appendix 1 data:

• Drilling method: NQ diamond drilling from surface.
• Total holes in the reported dataset:
  • 25MEDD002
  • 25MEDD002A
  • 25MEDD003
  • 26MEDD004
  • 26MEDS001

• Holes 25MEDD002 and 25MEDD002A were abandoned before reaching target depth.
• Hole 26MEDS001 was drilled to locate an interpreted shaft and was not designed as an exploration hole.

The company reports anomalous gold intersected in 25MEDD002 and 26MEDS001, however no significant results (NSR) were returned from 25MEDD002A or 25MEDD003. All assay results are reported at a 0.75 g/t Au lower cut-off, with up to 3 m of internal sub-grade allowed in significant intervals.

Selected assay highlights

The following summary focuses on reported anomalous intervals. Full details are contained in Appendix 1 of the ASX announcement.

Hole 25MEDD002

Hole 26MEDS001 (shaft-location test hole)

The 11.9 g/t Au interval over 0.40 m in hole 26MEDS001 is a key data point. It was intersected in a hole drilled for shaft location rather than exploration targeting. According to Black Horse Mining Ltd, this result was not the primary objective of the hole but indicates that gold-bearing structures occur in the vicinity of the interpreted shaft location.

The announcement also notes that core loss occurred within some reported intervals, particularly where historical workings and strong alteration are present. In addition, core recoveries were better in unmineralised country rock below the weathering horizon (approximately 80 m to 120 m depth).

Sampling and QAQC included half-core and, in some weakly competent zones, split core using a spatula, along with Photon Assay on 500 g samples at Onsite Laboratory Services (Bendigo) and use of certified reference standards, blanks, and duplicates at approximately 1:20 ratio. These technical details provide context for how the data has been generated and how the company is planning to refine sampling in poor ground conditions.

Upcoming drill programme: larger and more targeted

With the UDR1200 rig mobilised and planning advanced, the next phase of drilling at Mt Egerton is designed to build on the initial data set from the maiden campaign. Furthermore, the Black Horse Mining Mt Egerton drilling and Sister Rose Adit permit combination signals a more integrated and targeted exploration approach going forward.

According to the announcement and JORC Table 1 commentary:

• Planned programme scale

  • ~4,000 m of diamond drilling.
  • Approximately 10 holes.
  • Drilled from surface using NQ diamond core.

• Target themes

  • Unmined portions and extensions of known mineralisation as defined by historic workings.
  • Deeper parts of the deposit to test below previously mined or drilled levels.
  • Areas where the refined 3D model, supported by adit access, suggests potential continuity of lodes.

• Data and model integration

  • Drilling is being carried out broadly perpendicular to the main mineralised trends where terrain permits.
  • All new data will feed into a refined 3D geological model incorporating historical drilling and mining records, modern geophysical surveys, and underground mapping once the Sister Rose Adit is re-established.

The company also states that the first phase of diamond drilling is under review to determine the most appropriate sampling method in zones with poor ground conditions and historical voids. This type of review is common in early campaigns and can affect how future core is handled in highly altered or fractured zones.

Mt Egerton project setting and geological context

The ASX announcement provides a detailed JORC Code Table 1, outlining the geological setting of the Mt Egerton Gold Project. Key elements include:

• Location

  • Southwestern portion of the Bendigo Zone within the Lachlan Fold Belt in Victoria.
  • Tenements include Retention Licence RL2018 covering approximately 1,174.4 hectares, Exploration Licence EL6417 (45 graticular sections), and Exploration Licence application EL8628 (53 graticular sections).

• Host rocks

  • Early Ordovician turbidite sequences of the Castlemaine Supergroup, composed mainly of siltstone, shale, and sandstone, which have been tightly folded.
  • Late Devonian Mt Egerton Granodiorite outcrops to the west, with thermal effects possibly overlapping historically worked areas.
  • Near-surface cover includes Neogene-Pleistocene alkali basalt flows (Newer Volcanic Group).

• Mineralisation style

  • Gold hosted in north-south trending quartz reefs.
  • Higher grades occur in specific structural settings.
  • The company describes similarities to major Victorian gold deposits such as Ballarat, Bendigo, and Fosterville, although Mt Egerton remains at the exploration stage.

This context is important because it positions Mt Egerton within a well-known gold province and helps explain why Black Horse Mining Ltd is focused on detailed structural modelling and targeted diamond drilling.

Investor perspective: why this update matters

From an investor standpoint, the 19 June 2026 ASX announcement highlights several elements that may influence how the Mt Egerton project is assessed.

1. Activity level is increasing

A high-capacity UDR1200 rig is on site with drilling expected to commence within days. The 4,000 m / 10-hole programme is materially larger than the maiden campaign and, consequently, is likely to generate regular news flow as holes are completed and assays are reported.

2. Adit work supports improved targeting

The permit to re-establish the Sister Rose Adit provides an opportunity to access historical workings directly, confirm the position of the Sister Rose shaft, and better align surface drilling with underground structures. For investors, this may reduce geological uncertainty around where capital is deployed in the drilling programme.

3. Early-stage results include high-grade intervals

Anomalous gold in 25MEDD002 and 26MEDS001 confirms that gold-bearing structures occur in the current target area. Furthermore, the 11.9 g/t Au intercept in a non-exploration shaft-location hole offers a datapoint that supports the presence of high-grade zones, subject to further drilling.

4. Geological setting is consistent with known Victorian gold systems

The Bendigo Zone and Castlemaine Supergroup are well-documented hosts to major gold deposits. Black Horse Mining Ltd references structural similarities between Mt Egerton and producing Victorian fields, while noting that the project is still in the exploration phase.

5. Clear near-term milestones

The combination of drilling commencement, adit refurbishment, and progressive assay reporting outlines a defined short-term catalyst pipeline:

Summary: monitoring Black Horse Mining Ltd at Mt Egerton

The latest ASX announcement positions Black Horse Mining Ltd at an active stage in the exploration cycle at the Mt Egerton Gold Project. The Black Horse Mining Mt Egerton drilling and Sister Rose Adit permit developments collectively represent a significant step forward in the company's exploration strategy.

The key elements are as follows:

• Mobilisation of a UDR1200 diamond drill rig and a planned 4,000 m, 10-hole programme.
• Regulatory approval to re-establish the Sister Rose Adit, with refurbishment expected to finish within two months and subsequent access to historical workings on the Sister Rose and Rose lodes.
• Final maiden programme results showing anomalous gold in 25MEDD002 and 26MEDS001, including a high-grade 11.9 g/t Au interval in a shaft-location hole.
• A geological setting within the Bendigo Zone of the Lachlan Fold Belt, with gold hosted in north-south quartz reefs.

For investors following Black Horse Mining Ltd, the focus over the coming months is likely to centre on drill progress, assay outcomes from the expanded programme, and any updates to the 3D geological model once underground access via the Sister Rose Adit is re-established.

Want to Learn More About Black Horse Mining's Mt Egerton Gold Project?

With a high-capacity diamond rig now on site, a 4,000-metre drill programme underway, and regulatory approval secured to re-establish the Sister Rose Adit, Black Horse Mining Ltd (ASX: BHL) is entering an active phase at Mt Egerton. Investors looking to stay across drill results, project milestones, and the company's broader exploration strategy can find out more by visiting the Black Horse Mining website.