Prime Intersects 42 g/t Gold Equivalent over 1 m at Guadalupe

VANCOUVER, Dec. 10, 2024 - Prime Mining Corp. ("Prime" or the "Company") (TSX: PRYM) (OTCQX: PRMNF) (Frankfurt: 04V3) is reporting expansion drilling results from the Company's Los Reyes Project (the "Project"), located in Sinaloa State, Mexico. These results are from 2024 drilling at the Guadalupe Trend and are not included in the Company's October 15, 2024, Mineral Resource Estimate ("MRE").

Expansion Drilling Highlights at Guadalupe

The Company is reporting 4 core holes at Guadalupe East, located in the south-east end of the Guadalupe Trend with the following highlights:

• 42.07 grams per tonne ("g/t") gold-equivalent ("AuEq") (14.25 g/t Au and 2,150.0 g/t Ag) over 1.0 metres ("m") estimated true width ("ETW") in hole 24GE-160, and:
  • 11.33 g/t AuEq (3.34 g/t Au and 617.4 g/t Ag) over 1.3 m ETW, including:
  • 21.28 g/t AuEq (6.27 g/t Au and 1,160.0 g/t Ag) over 0.7 m ETW;
• 5.32 g/t AuEq (1.80 g/t Au and 271.8 g/t Ag) over 2.4 m ETW in hole 24GE-162, including:
  • 7.34 g/t AuEq (2.41 g/t Au and 381.0 g/t Ag) over 1.5 m ETW.
    

Prime Mining Corp. Chief Executive Officer Scott Hicks commented, "Guadalupe East continues to provide exceptional high-grade results. In targeting the sparsely drilled 700m gap between the main 'Laija' area at Guadulupe East and the Echeguren Shaft, we continue to find mineralization. Drill hole 24GE-160 is particularly outstanding for its high-grade gold and silver, measuring half an ounce of gold and over 2 kilograms of silver over a metre in length. Both drill holes 24GE-160 and 24GE-162 demonstrate the potential for further expansion of mineralized material, amenable for underground extraction."

Scott Smith, Executive Vice President of Exploration, added, "Drilling in the San Manuel vein area of Guadalupe East targeted a set of north-dipping veins in the footwall of the Estaca vein. Today's drill results demonstrate the high grades typical of Guadalupe East and are located over 400m away from the main Guadalupe East resource area. This part of the trend demonstrates strong exploration potential for further antithetic vein structures to be discovered with mineralization open in several directions. We believe the old mine workings, including the Echeguren Shaft, which is approximately 300m from these highlight holes, provide good hunting ground for further discovery, given the mineralization we have found to-date by referencing these workings for drill targeting."

Figure 1: Expansion drilling update

Guadalupe East 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

Guadalupe East:

Three principal vein sets have been the focus of both historical mining operations and recent exploration at Guadalupe East (Estaca, San Manuel, and San Nicolas). In the Laija area, high-grade gold and silver mineralization is hosted in the steeply south-dipping Estaca vein and north-dipping antithetic veins emanating from its hanging wall. Further to the east, approaching the Echeguren Shaft area, high-grade mineralization is also hosted in the moderately north-dipping San Manuel and San Nicolas vein sets, which appear to truncate on the footwall of the Estaca vein. All three principal vein sets remain open in several directions and will continue to be the focus of exploration at Guadalupe East.

The drillholes released today targeted the extension of the San Manuel vein set projected along-strike and down-dip from historical mine workings. The intercepts in 24GE-160 represent a 60m step out along strike to the west from 23GE-144 (8.17 g/t Au and 1,498 g/t Ag over 0.75m) and confirm the continuity of high-grade gold and silver mineralization hosted in the San Manuel area. The intercept in 24GE-160 similarly represents a 60m step out from stopes generated in the 2024 MRE. The Company, therefore, believes that both drillholes are likely to further expand underground mineable mineralization at Guadalupe East in future Resource estimates. Additionally, the drillholes released today are roughly 330m west of the Echeguren Shaft area, a historical mine exploited in the early 1900's for very high-grade silver. We believe that significant potential exists to expand mineralization along strike of the San Manuel vein set toward and beyond the Echeguren Shaft.

Figure 2: Guadalupe Trend drilling update

Figure 3: Guadalupe Trend (GE Area) 3D View

2024 Outlook

Given the results from Prime's success-based drilling program, the Company has expanded its fiscal 2024 program to 50,000 metres from 40,000 metres. The drill program 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 and others to further develop the resource potential at Los Reyes.

Links to Figures:

• Figure 1 - Expansion drilling update
• Figure 2 - Guadalupe Area drilling update
• Figure 3 - Guadalupe Area (Guadalupe East) 3D View
  

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 $59 million on direct exploration activities and has completed over 210,000 metres of drilling. On October 15, 2024, Prime announced an updated multi-million-ounce high-grade open pit constrained resource based on exploration drilling up to July 17, 2024 (see the October 15, 2024, press release for more information).

October 15, 2024 Resource Statement
(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.
   

Drilling is ongoing and suggests that the three known main resource trends (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.

Additional Notes

Prime's MRE as of October 15, 2024 is classified in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum ("CIM") "CIM Definition Standards - For Mineral Resources and Mineral Reserves" adopted by the CIM Council (as amended, the "CIM Definition Standards") and in accordance with the requirements of NI 43-101. Mineral resources are not mineral reserves and do not have demonstrated economic viability.

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; "g/t" or "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 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.

Gold equivalent grades are calculated based on an assumed gold price of US$1,950 per ounce and silver price of $25.24 per ounce, based on the formula AuEq grade (g/t) = Au grade + (Ag grade x $25.24 / $1,950). Metallurgical recoveries are not considered in the in-situ grade estimate but are estimated to be 95.6% and 81% for gold and silver, respectively, when processed in a mill, and 73% and 25% respectively when heap-leached. Additional details are available in the associated 2024 Technical Report.

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.

For further information, please visit https://www.primeminingcorp.ca/ or direct enquiries to:

Scott Hicks
CEO & Director

Indi Gopinathan
VP Capital Markets & Business Development

Prime Mining Corp.
710 - 1030 West Georgia St.
Vancouver, BC V6E 2Y3 Canada
+1(604) 238-1659
info@primeminingcorp.ca

Cautionary Notes to U.S. Investors Concerning Resource Estimates
This news release has been prepared in accordance with the requirements of the securities laws in effect in Canada, which differ from the requirements of the U.S. securities laws. In particular, and without limiting the generality of the foregoing, the terms "mineral reserve", "proven mineral reserve", "probable mineral reserve", "inferred mineral resources," "indicated mineral resources," "measured mineral resources" and "mineral resources" used or referenced in this presentation are Canadian mineral disclosure terms as defined in accordance with NI 43-101 under the guidelines set out in the CIM Standards. The CIM Standards differ from the mineral property disclosure requirements of the U.S. Securities and Exchange Commission (the "SEC") in Regulation S-K Subpart 1300 (the "SEC Modernization Rules") under the U.S. Securities Act of 1933, as amended (the "Securities Act"). As a foreign private issuer that is eligible to file reports with the SEC pursuant to the multijurisdictional disclosure system, the Company is not required to provide disclosure on its mineral properties under the SEC Modernization Rules and will continue to provide disclosure under NI 43-101 and the CIM Standards. Accordingly, the Company's disclosure of mineralization and other technical information may differ significantly from the information that would be disclosed had the Company prepared the information under the standards adopted under the SEC Modernization Rules.

Forward Looking Information
This news release contains certain "forward-looking information" and "forward-looking statements" within the meaning of Canadian securities legislation as may be amended from time to time, including, without limitation, statements regarding the perceived merit of the Company's properties, including additional exploration potential of Los Reyes, potential quantity and/or grade of minerals, the potential size of the mineralized zone, metallurgical recoveries, and the Company's exploration and development plans in Mexico. Forward-looking statements are statements that are not historical facts which address events, results, outcomes, or developments that the Company expects to occur. Forward-looking statements are based on the beliefs, estimates and opinions of the Company's management on the date the statements are made, and they involve several risks and uncertainties. Certain material assumptions regarding such forward-looking statements were made, including without limitation, assumptions regarding the price of gold, silver and copper; the accuracy of mineral resource estimations; that there will be no material adverse change affecting the Company or its properties; that all required approvals will be obtained, including concession renewals and permitting; that political and legal developments will be consistent with current expectations; that currency and exchange rates will be consistent with current levels; and that there will be no significant disruptions affecting the Company or its properties. Consequently, there can be no assurances that such statements will prove to be accurate and actual results and future events could differ materially from those anticipated in such statements. Forward-looking statements involve significant known and unknown risks and uncertainties, which could cause actual results to differ materially from those anticipated. These risks include, but are not limited to: risks related to uncertainties inherent in the preparation of mineral resource estimates, including but not limited to changes to the cost assumptions, variations in quantity of mineralized material, grade or recovery rates, changes to geotechnical or hydrogeological considerations, failure of plant, equipment or processes, changes to availability of power or the power rates, ability to maintain social license, changes to interest or tax rates, changes in project parameters, delays and costs inherent to consulting and accommodating rights of local communities, environmental risks, title risks, including concession renewal, commodity price and exchange rate fluctuations, risks relating to COVID-19 and other future pandemics, delays in or failure to receive access agreements or amended permits, risks inherent in the estimation of mineral resources; and risks associated with executing the Company's objectives and strategies, including costs and expenses, as well as those risk factors discussed in the Company's most recently filed management's discussion and analysis, as well as its annual information form dated March 25, 2024, available on www.sedarplus.ca. Except as required by the securities disclosure laws and regulations applicable to the Company, the Company undertakes no obligation to update these forward-looking statements if management's beliefs, estimates or opinions, or other factors, should change.