June 2024 Quarterly Activities Report

Castillo Copper Limited (LSE and ASX: CCZ), a base metal explorer primarily focused on copper across Australia and Zambia, is pleased to present its latest quarterly report for the period 1 April 2024 to 30 June 2024.

HIGHLIGHTS:

Big One Deposit Surface Sampling Campaign Revealed1

• Comprehensive three-day surface sampling campaign devised, concentrating on eight areas across the Big One Deposit with historical anomalous surface copper and/or high conductivity zones.
• Campaign was developed with reference to an Induced Polarisation (IP) survey undertaken by Castillo in 2020, which evidenced:

o Significant incremental copper mineralisation along north-trending fault structures, rather than within the trachyte dyke, and

o Significant untested bedrock conductor north of the line of lode, materially larger than the high-grade anomaly drilled in 2020.

Strategic Asset Portfolio Review - Additional Resolutions2

• Board committed to advancing the NWQ Copper Project, which has > 20 known prospects, and in the context of a copper bull market.
• Strategic partners being sought to develop remaining assets in NSW and Zambia.

Cash and Liquid Investments

• Cash on hand at end of quarter totalled $1.118 million.
• Rehabilitation Security Bonds totalled $486,960, of which $172,900 is expected to be converted to cash within 1 month.
• Castillo holds 13,440,861 Rimfire Pacific Mining Ltd (ASX: RIM) shares which as at 28 June 2024 had a market value of ~$376,000.

Eduardo Robaina, Non-executive Director, commented: "We're tracking well against the reinvigorated strategy that was devised by the Board at the end of 2023, where it was unanimously agreed that the Company's focus would prioritise the development of the NWQ Copper Project. This, in turn, resulted in the determination that our remaining assets - deemed non-core - should be either divested or pursued as a Joint Venture.

"In Q1, to put this strategy in motion, we divested ourselves of two of our four tenements at the Broken Hill Project. Furthermore, in this latest Quarter, we announced a soil sampling campaign that would reconcile past results and help to inform future drilling programs at our flagship NWQ Copper Project."

PAST WORK AT BIG ONE PROVES DEVELOPMENT POTENTIAL OF PROSPECT

The Big One Deposit has long been a prospect of interest. In 2022, the Company delivered a maiden, JORC 2012 compliant Mineral Resource Estimate (MRE)3 of 2.1Mt @ 1.1% Cu for 21,886t contained metal, which included the following high grade drilling results:4

• 40m @ 1.64% from surface incl: 11m @ 4.40% from 24m, 5m @ 7.34% from 28m and 1m @ 16.65% from 29m (BO_303RC)
• 44m @ 1.19% Cu from surface incl: 14m @ 3.55% from 27m, 3m @ 10.88% from 27m and 1m @ 12.6% from 37m (BO_301RC)

FOCUS AREA OF CAMPAIGN DEFINED

Non-Executive Director and Chief Geologist, Joel Logan, devised a targeted soil sampling campaign; covering eight highly prospective areas across the Big One Deposit - north and south of the 1,200m line of lode (Figure 1).

FIGURE 1: BIG ONE DEPOSIT LINE OF LODE AND FOCUS AREAS FOR CAMPAIGN

RATIONALE FOR CAMPAIGN PARAMETERS

A previous IP survey undertaken by Castillo in 2020, comprised six lines ranging from 500-700m long and spaced 200m apart over the 1,200m line of lode.

FIGURE 2: LINE LOCATIONS TRANSVERSING BIG ONE DEPOSIT

The 2020 IP survey interpretations at the time suggested that there was a significant untested bedrock conductor north of the line of lode that was materially larger than the high-grade anomaly drilled in 2020 (Figure 2).

Further, interpretations from surface sampling implied that there was incremental copper mineralisation along north-trending fault structures, rather than constrained within the trachyte dyke.

FIGURE 3: LINE 3, NEWLY IDENTIFIED BEDROCK CONDUCTORS

GOSSAN FORMATIONS REQUIRING FURTHER ASSESSMENT

Based on historical surface observations, ~200m north of the line of lode is a sizable, potential mineralised gossan that has been identified for thorough assessment for its underlying copper potential.

Gossan formations are known to act as a 'marker' for subsurface ore deposits, and are generally observed as rock that is intensely oxidised, decomposed or weathered in appearance.

PURPOSE OF CAMPAIGN

The Scope of Work is designed to progress and/or enable the following developments:

• Detailed geological mapping across the eight zones.
• Soil and/or rock chip sampling.
• Reconnaissance of potential future RC and diamond core sites.
• Explore magnetic susceptibility and pXRF measurements on any soil or rock chip samples collected.
• Record any other pertinent geological observations while in the field.

METHOD TO DETERMINE THE NEXT STEPS

The process following the three-day Soil Sampling Campaign is as follows:

• All samples to be sent to the laboratory for assaying.
• Once the full suite of geochemical results is returned, Castillo will reconcile results with historical observations / 2020 IP survey.
• Castillo will then devise high conviction test-drill targets to potentially extend known mineralisation north of the line of lode.

Cash and Liquid Investments

Cash on Hand

Cash on hand at end of quarter totalled $1.118 million.

Rehabilitation Security Bonds

Rehabilitation Security Bonds totalled $486,960 at quarter end, of which $172,900 is expected to convert to cash within 1 month.

Listed Investments

Castillo holds 13,440,861 Rimfire Pacific Mining Ltd (ASX: RIM) shares which as at 28 June 2024 had a market value of ~$376,000.

R&D Tax Incentive

An income tax refund of $182,756 due to the R&D Tax Incentive claim by Castillo is expected to be received within 2 months.

Information Required Under ASX Listing Rules

ASX LR 5.3.5

During the Quarter $72,000 was paid to related parties of the Company relating to non-executive director fees and exploration consulting fees paid to an entity controlled by a related party.

ASX LR 5.3.1

A summary of the exploration expenditure incurred during the quarter is set out below:

Table 1: Summary of Exploration Expenditure

ASX LR 5.3.3

In accordance with ASX Listing Rule 5.3.3, a schedule of Company's tenements as at 30 June 2024 can be found at Appendix B.

Castillo Copper is listed on the LSE and ASX under the ticker "CCZ".

APPENDIX A: Key Projects

Figure 1: BHA Project, Broken Hill Region (Source: CCZ Geology Team)

Figure 2: Zambia Copper-Belt Projects (Source: CCZ Geology Team)

Figure 3: Historic drilling results in SYG's Mining Lease (Source: Refer to CCZ ASX Release 11 November 2019)

Figure 4: NWQ Copper Project, Mt Isa Region (Source: CCZ Geology Team)

APPENDIX B: Interest in mining tenements held

Table 1: Jackaderry (Cangai), New England Orogen in NSW

Table 2: Broken Hill, located within a 20km radius of Broken Hill in NSW

Table 3: Mt Oxide, Mt Isa region in North West Queensland

Appendix 5B

Mining exploration entity or oil and gas exploration entity

quarterly cash flow report

Name of entity

Castillo Copper Ltd

• entities
• tenements
• property, plant and equipment
• investments
• other non-current assets

1 Comprises director's fees for the quarter. 2 Comprises exploration expenditure paid to Field Crew Pty Ltd, a related entity of former director David Drakeley.

Answer: N/A

Answer: N/A

Answer: N/A

Compliance statement

2 This statement gives a true and fair view of the matters disclosed.

Date: 30 July 2024

Authorised by: The Board of Directors

(Name of body or officer authorising release - see note 4)

Notes