High Grade Mineralization Expected to Contribute to Resource Growth While Providing Underground and Open Pit Optionality

Prime Mining Corp. (TSX: PRYM) (OTCQX: PRMNF) (Frankfurt: 04V3) is reporting generative drilling results from the Company’s Los Reyes Project, located in Sinaloa State, Mexico. These results are from 2024 drilling at the Fresnillo and Mariposa targets and are not included in the Company’s October 15, 2024, Mineral Resource Estimate.

Generative Drilling Highlights: Fresnillo – A Prime Original Discovery

The Company is reporting 14 core holes, two that intersected only Fresnillo structures, four that intersected both Noche Buena and Fresnillo structures, and eight that intersected Mariposa structures. Fresnillo is located between the Z-T and Central Trends with the following highlights in today’s results:

• 1.99 g/t gold-equivalent (1.82 g/t Au and 13.1 g/t Ag) over 9.6 m estimated true width in hole 24NB-75, including:
  • 20.02 g/t AuEq (18.4 g/t Au and 125.0 g/t Ag) over 0.8 m ETW;
• 2.83 g/t AuEq (2.52 g/t Au and 23.6 g/t Ag) over 6.2 m ETW in hole 24NB-71, including:
  • 5.99 g/t AuEq (5.38 g/t Au and 47.0 g/t Ag) over 2.8 m ETW;
• 1.46 g/t AuEq (1.08 g/t Au and 29.7 g/t Ag) over 9.8 m ETW in hole 24NB-69, including:
  • 6.76 g/t AuEq (5.35 g/t Au and 109.0 g/t Ag) over 1.4 m ETW;
• 1.45 g/t AuEq (1.17 g/t Au and 21.6 g/t Ag) over 6.8 m ETW in hole 24FRE-29.

Prime Mining Corp. Chief Executive Officer Scott Hicks commented, “Fresnillo is an exciting early stage generative target at Los Reyes. Today, we are sharing results that demonstrate a significant extension of approximately 120 metres up-dip of high grade, near-surface mineralization with both underground and open pit optionality and with further potential to continue expanding mineralization.”

Scott Smith, Executive Vice President of Exploration, added, “Holes 24NB-69, -70, -71, and -75, and 24FRE-29 resulted in the extension of high-grade mineralization near-surface and roughly 120 metres up-dip from the stopes generated in the 2024 MRE for the Fresnillo target area. As these drillholes help to ‘fill in’ more sparsely drilled areas, their addition is likely to drive an increase to reportable Inferred ounces in future estimates for the Fresnillo area. Mineralization remains open along strike to the northwest of 24NB-69 and 24FRE-29 and will be tested by in-progress hole 25FRE-30.”

Figure 1: Generative drilling update

Generative Drill Hole Highlights¹

Notes:

1. A complete table of assay results from all deposits and all secondary zones intersected utilizing a 0.20 g/t Au cut-off is on the Company’s website.
2. Estimated True Widths (ETW) are estimated based on drill hole geology or comparisons with other on-section drill holes.
3. Au Equivalent (AuEq) grade is calculated as Au g/t + (Ag g/t x ($25.24/$1950)) where $25.24 and $1950 are the price of one ounce of Ag and Au respectively (in US dollars).
4. Composite assay grades presented in summary tables are calculated using a Au grade minimum average of 0.20 g/t or 1.0 g/t as indicated in “Au Cut-off” column of Summary Tables. Maximum internal waste included in any reported composite interval is 3.00 m. The 1.00 g/t Au cut-off is used to define higher-grade “cores” within the lower-grade halo.

INTERPRETATION

Fresnillo:

Fresnillo, located between the Z-T and Central Trends, was first drilled as part of Prime’s 2022 drill program. It is a highly prospective earlier stage target which had no historical drilling or known workings. Fresnillo was defined by Prime’s mapping and geochemical sampling programs. Prime drilling to-date has intercepted several thick mineralized structures.

24NB-69, -70, -71, and -75, and 24FRE-29 resulted in the near-surface, roughly 120m up-dip extension of high-grade mineralization from stopes generated in the 2024 MRE for the Fresnillo target area. Further, these drillholes were completed in a sparsely drilled area which did not meet data spacing criteria for open pit or underground Inferred Resources in the 2024 MRE. Their addition is therefore likely to drive an increase in reportable Inferred ounces in future estimates for the Fresnillo area. Mineralization remains open along strike to the northwest of 24NB-69 and 24FRE-29 and will be tested by planned hole 25FRE-30.

Mariposa:

Prime is also releasing eight holes from the Mariposa target. These holes were drilled from the hanging wall on the west side of the main Z-T structure into the target area with the intention of gaining a greater understanding of the structural setting. Existing access at Mariposa limited the drill pad locations but results have confirmed the continuation of the Z-T structure at Mariposa. Prime intends to extend access and continue expansion drilling in the Mariposa area in 2025.

Figure 2: Fresnillo drilling update

Figure 3: Fresnillo long section with drill holes highlighted (A-A’)
* intercepts noted in long section below are along multiple structures*

Figure 4: Fresnillo cross section B-B’

Outlook

Prime will continue to evaluate drilling plans using its success-based approach into 2025. This evaluation will also include prioritization of targets based on probability of resource development and generative area discovery potential.

Prime has completed approximately 1,500 metres of drilling year to date. Drilling is currently suspended, with six drill rigs currently on site at Los Reyes and drillers on standby. The exploration team is utilizing this opportunity to advance interpretation of geological data and soil samples in support of target identification. Exploration in 2025 will be focused on:

• Extending the high-grade Z-T Area shoots that remain open at depth, as well as along strike, both north and south.
• Expanding the known high-grade mineralization at Guadalupe East.
• Increasing the Central Area resource through additions at Noche Buena and its connection to San Miguel East.
• Generative target drilling of high-grade intercepts at Las Primas, Mariposa, Fresnillo and others to further develop the resource potential at Los Reyes.

Links to Figures:

• Figure 1 – Generative drilling update
• Figure 2 – Fresnillo drilling update
• Figure 3 – Fresnillo long section with drill holes highlighted (A-A’)
• Figure 4 – Fresnillo cross section (B-B’)

Links to Tables:

• Table 1 – Drill Intercepts in this Release
• Table 2 – Drill Intercepts to Date

About the Los Reyes Gold and Silver Project

Los Reyes is a high-grade, low-sulphidation epithermal gold-silver project located in Sinaloa State, Mexico. Since acquiring Los Reyes in 2019, Prime has spent more than $62 million on direct exploration activities and has completed over 220,000 metres of drilling. On October 15, 2024, Prime announced an updated multi-million-ounce high-grade open pit and underground resource based on exploration drilling up to July 17, 2024.

October 15, 2024 Resource Statement¹
(based on a $1950/oz gold price, $25.24/oz silver price, economic-constrained estimate)

1. Refer to the Additional Notes section for the gold equivalent grade (“AuEq”) calculation method and further information.

Exploration drilling suggests that the three known main deposit areas (Guadalupe, Central and Z-T) are larger than previously reported. Potential also exists for new discoveries where mineralized trends have been identified outside of the currently defined resource areas. Historic operating results indicate that an estimated 1 million ounces of gold and 60 million ounces of silver were recovered from five separate operations at Los Reyes between 1770 and 1990. Prior to Prime’s acquisition, recent operators of Los Reyes had spent approximately US$20 million on exploration, engineering, and prefeasibility studies.

QA/QC Protocols and Sampling Procedures

Drill core at the Los Reyes project is drilled in predominately HQ size (63.5 millimetres “mm”), reducing to NQ (47.6 mm) when required. Drill core samples are generally 1.50 m long along the core axis with allowance for shorter or longer intervals if required to suit geological constraints. After logging intervals are identified to be sampled, the core is cut and one half is submitted for assay. RC drilling returns rock chips and fines from a 133.35 mm diameter tricone bit. The returns are homogenized and split into 2 halves, with one half submitted for analysis and the other half stored.

Sample QA/QC measures include unmarked certified reference materials, blanks, and field duplicates as well as preparation duplicates are inserted into the sample sequence and make up approximately 8% of the samples submitted to the laboratory for each drill hole.

Samples are picked up from the Project by the laboratory personnel and transported to their facilities in Durango or Hermosillo Mexico, for sample preparation. Sample analysis is carried out by Bureau Veritas and ALS Labs, with fire assay, including over limits fire assay re-analysis, completed at their respective Hermosillo, Mexico laboratories and multi-element analysis completed in North Vancouver, Canada. Drill core sample preparation includes fine crushing of the sample to at least 70% passing less than 2 mm, sample splitting using a riffle splitter, and pulverizing a 250-gram split to at least 85% passing 75 microns.

Gold in diamond drill core is analyzed by fire assay and atomic absorption spectroscopy of a 30 g sample (code FA430 or Au-AA23). Multi-element chemistry is analyzed by 4-Acid digestion of a 0.25-gram sample split (code MA300 or ME-ICP61) with detection by inductively coupled plasma emission spectrometer for a full suite of elements.

Gold assay techniques FA430 and Au-AA23 have an upper detection limit of 10 ppm. Any sample that produces an over-limit gold value via the initial assay technique is sent for gravimetric finish via method FA-530 or Au-GRA21. Silver analyses by MA300 and ME-ICP61 have an upper limit of 200 ppm and 100 ppm, respectively. Samples with over-limit silver values are re-analyzed by fire assay with gravimetric finish FA530 or Au-GRA21.

Both Bureau Veritas and ALS Labs are ISO/IEC accredited assay laboratories.

Qualified Person

Scott Smith, P.Geo., Executive Vice President of Exploration, is a Qualified Person for the purposes of NI 43-101 and has reviewed and approved the technical content in this news release.

About Prime Mining

Prime is managed by an ideal mix of successful mining executives, strong capital markets personnel and experienced local operators all focused on unlocking the full potential of the Project. The Company has a well-planned capital structure with a strong management team and insider ownership. Prime is targeting a material resource expansion at Los Reyes through a combination of new generative area discoveries and growth, while also building on technical de-risking activities to support eventual project development.