Prime Mining Corp. (TSX: PRYM) (OTCQX: PRMNF) (Frankfurt: 04V3) is reporting expansion drilling results from the Company’s Los Reyes Project, located in Sinaloa State, Mexico. These results are from 2024 drilling at the Z-T Area and are not included in the Company’s May 2, 2023 Mineral Resource Estimate.

Expansion Drilling Highlights in the Z-T Area: Tahonitas

The Company is reporting 15 core holes at Tahonitas with the following highlights:

• 7.68 grams per tonne gold-equivalent (5.83 gpt Au and 142.7 gpt Ag) over 7.7 metres  estimated true width in hole 24TA-116, including:
  • 31.49 gpt AuEq (24.31 gpt Au and 554.7 gpt Ag) over 1.8 m etw, including:
  • 55.72 gpt AuEq (44.1 gpt Au and 898.0 gpt Ag) over 0.6 m etw;
• 1.98 gpt AuEq (1.21 gpt Au and 59.7 gpt Ag) over 16.9 m etw in hole 24TA-110, including:
  • 3.99 gpt AuEq (2.41 gpt Au and 122.0gpt Ag) over 4.5 m etw;
• 23.97 gpt AuEq (7.66 gpt Au and 1,260.0 gpt Ag) over 0.8 m etw in hole 24TA-111.

Prime Mining Corp. Chief Executive Officer Scott Hicks commented, “High grade mineralization at meaningful widths continues to develop at Tahonitas at the south-east end of the Z-T Trend, demonstrating potential to grow the existing mineral resource estimate. We are excited to see the development of this new lobe at Tahonitas and the exceptional grades being registered, both for gold and silver. This area remains open and is targeted for additional drilling.”

Figure 1: Expansion drilling update

Tahonitas Drill Hole Highlights¹

^{1)   A complete table of assay results from all deposits and all secondary zones intersected utilizing a 0.20 gpt 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) is calculated as Au gpt + (Ag gpt x ($22/$1700)) where $22 and $1700 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 gpt or 1.0 gpt 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 gpt Au cut-off is used to define higher-grade “cores” within the lower-grade halo.}

INTERPRETATION

24TA-116 is located 250m along strike from the current resource pit bottom, and 24TA-112 is located 350m down dip from the current resource pit bottom (at a mid-intercept elevation of approximately 295m above sea level). 24TA-110, located at a similar elevation to 24TA-116 (mid-intercept of 330m above sea level) and 50m along strike, is also 700m up-dip from 24TA-112 showing the structure has significant width of mineralization with its 16.9m etw reported mineralized intercept. Step-out hole 24TA-111, located 400m from the pit crest (and 150 m down-dip from the prior south-eastern most intercept 23TA-100), returned high gold and outstanding silver grades from an intercept in the footwall of the main Tahonitas structure; this footwall structure may merge into the main Tahonitas structure along strike in the South Tahonitas area. The southeastern-most shoot of Z-T now has a modelled strike length of high-grade mineralization spanning 315m and remains open along strike and down-dip. Prime is currently drill testing (with drill hole 24TA-120) the 275 m gap between 24TA-114/-116 and 23TA-94. 24TA-119 is also being drilled to extend mineralization down dip.

The ongoing discovery of mineralization hosted at relatively shallow depths continues to suggest the following:

1. Shallow early-stage intersections that may support pit expansion to the southeast near surface.
2. Demonstrates that the Tahonitas structure continues to be mineralized for 350m along strike from the south-east pit crest.
3. The potential to discover more high-grade plunging shoots with continued drilling at depth within the new southeast strike extension and potentially high-margin underground feed.

As noted in earlier Z-T Trend releases focused on Tahonitas, the high-grade plunging shoots are still open at depth and along strike in multiple areas along the Trend.

Figure 2: Z-T Area drilling update

Figure 3: Z-T Area long section with drill holes highlighted (A-A’)

Figure 4: Z-T Area (Tahonitas) cross section B-B’

2024 Outlook

Prime is targeting 40,000 metres in its 2024 drill program and will continue to evaluate drilling plans using its success-based approach. This evaluation will also include prioritization of targets based on probability of resource development and generative area discovery potential.

Five drill rigs are currently active on site at Los Reyes, with 2024 exploration 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, Mina and others to further develop the resource potential at Los Reyes.

Links to Figures:

• Figure 1 – Expansion drilling update
• Figure 2 – Z-T Area drilling update
• Figure 3 – Z-T Area long section with drill holes highlighted (A-A’)
• Figure 4 – Z-T Area (Tahonitas) 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 rapidly evolving high-grade, low sulphidation epithermal gold-silver project located in Sinaloa State, Mexico. Since acquiring Los Reyes in 2019, Prime has spent approximately CAD$48 million on direct exploration activities and has completed over 168,000 metres of drilling. On May 2, 2023, Prime announced an updated multi-million-ounce high-grade open pit constrained resource (see the May 2, 2023 press release for more details).

May 2, 2023 Resource Statement

Drilling is on-going and 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 millimetre “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.

Additional Notes

Metres is represented by “m”; “etw” is Estimated True Width and is based on drill hole geometry or comparisons with other on-section drill holes; “Au” refers to gold, and “Ag” refers to silver; “gpt” is grams per metric tonne; some figures may not sum due to rounding; Composite assay grades presented in summary tables are calculated using a Au grade minimum average of 0.20 gpt or 1.0 gpt 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 gpt Au cut-off is used to define higher-grade “cores” within the lower-grade halo.

Gold equivalent grades are calculated based on an assumed gold price of US$1,700 per ounce and silver price of $22 per ounce, based on the formula AuEq grade (gpt) = Au grade + (Ag grade x ($22 / $1,700)). Metallurgical recoveries are not considered in the in-situ grade estimate but are estimated to be 93% and 83% for gold and silver, respectively, when processed in a mill, and 72% and 25% respectively when heap-leached.

Qualified Person

Scott Smith, P.Geo., Executive Vice President of Exploration, is a qualified person for the purposes of National Instrument 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 Los Reyes 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.