Vancouver - Prime Mining Corp. ('Prime' or the 'Company') (TSX-V: PRYM), (OTCQB: PRMNF), (Frankfurt: A2PRDW), announces additional positive results from its continuing 15,000-metre first phase drill program ('Phase 1') at its wholly owned Los Reyes gold-silver project in Sinaloa state, Mexico.

The results include new drill core assays from the Guadalupe East and Zapote South deposits which are two of eight known gold-silver deposits that comprise the current mineral resource at Los Reyes. Twelve drill holes are being reported on, including seven holes from Guadalupe East, and five holes from Zapote South. An additional four drill holes have also been completed at Guadalupe East, each encountering the Estaca vein, with assays pending. A seventh drill rig has been added to the project as the Company pursues completion of Phase 1 drilling prior to the upcoming rainy season.

Key Highlights

Guadalupe East

Drill hole 21GE-03 targeted the Estaca vein at Guadalupe East in an area with no known historic mining or previous drilling to gain more geologic and structural controls and aid in further planning of step-out drilling. Access and topography constraints required hole 21GE-03 to be drilled at a high angle to the interpreted mineralized system. The drill hole successfully intercepted the Estaca vein with a drill core length of 58.0 metres ('m'), 11.6 m estimated true width ('etw'), returning 12 grams per tonne ('gpt') gold ('Au') and 724.6 gpt silver ('Ag'). Contained within this intercept are three discrete mineralized zones: two upper vein breccia zones separated by 3.5 m (0.7 etw) of waste and a lower mineralized stockwork unit separated from the lower vein breccia by 4.5 m (0.9 m etw) of waste. The first vein breccia intercept was 28.0 m (5.6 m etw) of 11.95 gpt Au and 1,122.1 gpt Ag and the second vein breccia intercept was 10.0 m (2.0 m etw) at 11.17 gpt Au and 909.3 gpt Ag. The lower stockwork unit intercept was 12.0 m (2.4 m etw) at 2.00 gpt Au and 120.9 gpt Ag.

Drill hole 21GE-03 intersected the Estaca vein approximately 125 m higher in elevation and nearly 70 m northwest of previously reported hole 21GE-01 which intersected 1 m at 3.25 gpt Au 380.0 gpt Ag, including 6.5 m at 6.51 gpt Au and 587.5 gpt Ag (described in our March 18, 2021 news release). These intercepts, and the historic intercepts in drill holes 12GV-02 and 12GV-03, establish that significant mineralization persists at shallower, open pit depths and the resource has expansion potential to the southeast.

Drill holes 21GE-09 and 21GE-10 have also intersected the Estaca vein in previously undrilled areas below historic mining. Drill holes 21GE-11 and 21GE-13 intersected the Estaca vein westwards toward the boundary of the current Guadalupe East pit-constrained Inferred resource. Assays are pending for these four drill holes.

Drill holes 21GE-05 and 21GE-07 intersected new mineralized structures adjacent to the Estaca vein. Hole 21GE-05 intercepted 1.5 m (1.4 m etw) at 50 gpt Au and 300.0 gpt Ag and hole 21GE-07 intersected 0.9 m (0.6 m etw) at 93.80 gpt Au and 829.0 gpt Ag. These new structures also potentially expand the current Guadalupe East pit-constrained Inferred resource.

Zapote South

Drill hole 21ZAP-15 intercepted 3 m (7.4 m etw) at 4.49 gpt Au and 67.9 gpt Ag, representing a 40.0 m step-out. Hole 21ZAP-15 is the most southerly intercept drilled at Zapote South to-date. Additionally, hole 21ZAP-14 intercepted 10.4 m (7.3 m etw) grading 2.12 gpt Au and 42.3 gpt Ag. Both holes demonstrate the potential to expand current open pit resources.

Drill hole 21ZAP-09 is an in-fill hole that intercepted 15.9 m (15.9 m etw) at 2.01 gpt Au and 35.7 gpt Ag plus another 23.4 m (23.4 m etw) at 5.56 gpt Au and 59.0 gpt Ag, including an interval with 8.6 m (8.6 m etw) at 14.09 gpt Au and 105.1 gpt Ag. Hole 21ZAP-09 provides significant missing silver information to the resource block model.

Chief Executive Officer, Daniel Kunz commented, 'We are excited to have encountered more bonanza grade gold and silver mineralization in ongoing drilling at Guadalupe East that has both open pit and now underground resource potential and that remains open at depth and to the south. Drilling the bonanza grade mineralization at Guadalupe East requires solving problems caused by historic workings, access logistics and the depth of targeted mineralization from surface. We have mobilized a more powerful drill rig to help address these challenges. At Zapote South, we are also seeing anticipated gold and silver grades that extend mineralization towards Tahonitas.'

The Estaca Vein - Guadalupe East

The Guadalupe structure was first mined as early as 1772, with the most active period of mining taking place between 1872 - 1938. The Estaca Vein is one of three principal veins mined at Guadalupe East yet remains largely untested by drilling. Drill campaigns by prior operators established a limited understanding of the true orientation of the vein. Targeting mineralization is challenging because of topography, access constraints and voids associated with historic mining. Only three of more than a dozen drill holes completed by prior operators intersected the bonanza-style mineralization previously mined at Guadalupe East. Current 3D modelling and re-interpretation of these drill intersections indicates a steep southwest dipping vein geometry. Mineralization is typical of low sulphidation epithermal systems, comprising massive to drusy, colliform to crustified adularia bearing quartz and quartz breccias.

This intercept was modified from the normal compositing criteria used to report in the previous news releases and this current news release to account for the overall length of mineralized intercept. Two intervals of 3.5 m (213.0 m - 216.5 m) and 4.5 m (226.5 m - 231.0 m) of internal waste did not meet the minimum 3.0 m requirement and minimum assay of 0.2 gpt Au to be included as internal dilution for the broader intercept. The broader interval is reported because the estimated true width of the internal waste component is only 0.7 m and 0.9 m respectively.

Drill hole 21GE-03 targeted the Estaca vein in an area that appears to have had no historic mining and is just outside the Guadalupe East planned Inferred resource open pit shell. Hole 21GE-03 intersected the Estaca vein at a high angle entering from the footwall through to the hanging wall. It intercepted a 58.0 m (11.6 m etw) mineralized package that includes two zones of internal waste totalling 8.0 m (1.6 m etw). The drill hole intercepted two mineralized vein and vein breccia zones separated by 3.45 m (0.7m etw) of waste rock, and a lower stockwork vein system separated from the upper veins by 4.5 m (0.9 m etw) of waste. The first interval was 28.0 m (5.6 m etw) of 11.95 gpt Au and 1,122.1 gpt Ag and the second consisted of 10.0 m (2.0 m etw) at 11.17gpt Au and 909.3 gpt Ag. Significant adularia and what has been interpreted as black colored silver sulphosalt minerals were noted in the drill core where the highest silver grades were reported. Approximately 4.5 m (0.9 m etw) of waste separates the lower mineralized vein with a mineralized stockwork zone grading 2.00 gpt Au and 120.9 gpt Ag over 12.0 m (2.4 m etw).

Four additional holes have been completed with assays currently pending. Holes 21GE-09 and 21GE-10 targeted the Estaca vein at a depth below the known historic workings. Holes 21GE-11 and 21GE-13 intersected the Estaca vein closer to the bottom of the current Inferred category open pit resource.

Major Drilling Group International Inc. has now mobilized a larger diamond drill rig. This rig has the capability of drilling to 800 m with NQ core and over 1000 m with BQ core and has started to target potential extensions of the Estaca vein along strike to the southeast and at depth. This rig is positioned to drill the mineralized system from the hanging wall to footwall. These are deep holes that will provide a better indication of geology and true thickness of the Estaca vein system. Follow up drilling will also target shallow areas of the resource where opportunities exist to potentially expand the open pit and access high-grade mineralization at shallower depths.

The San Nicolas Vein - Guadalupe East

San Nicolas, together with Estaca and San Manuel, is one of three principal veins historically mined underground at Guadalupe East and remains largely untested by drilling. Drill holes 21GE-05 and 21GE-07 have intercepted a high-grade, shallow vein breccia zone that dips to the north and is interpreted as a potential extension of the San Nicolas vein. Hole 21GE-05 intercepted 1.5 m (1.4 m etw) grading 10.50 gpt Au and 300.0 gpt Ag and hole 21GE-07 located 15.0 m down-dip from hole 21GE-05 intercepted 0.9 m (0.6 etw) grading 93.80 gpt Au and 829.0 gpt Ag. Hole 21GE-05 also encountered a lower zone of mineralization intercepting 7.8 m (3.9 m etw) grading 0.45 gpt Au and 37.5 gpt Ag. Additional shallow drilling using oriented core technology will help determine the extent and alignment of these structures.

Zapote South

Mineralization at Zapote South consists primarily of white to grey crystalline to chalcedonic quartz, quartz breccia and stockwork exploiting 45-degree southwest dipping fault structures within or along the margins of rhyolite dykes that intrude both andesitic tuffs and rhyolite. Quartz is massive-to-crustiform, locally displaying colliform to bladed replacement textures. Higher-grade intervals are marked by finely banded green adularia. Gold distribution appears to be zoned within the quartz bearing structure. The structure appears to have 1.0 to 5.0 m thick, higher-grade core, where grades exceed 4.0 gpt Au. This high-grade core is contained within a much broader 10.0 m plus thick zone of mineralization that has a gold grades of greater than 0.2 gpt. Higher-grade structures appear continuous from section to section locally.

The optimum elevation for higher-grade mineralization at Zapote South appears to be between 710 m and 580 m elevation above sea level ('asl'). Quartz and quartz breccia zones become generally narrower and lower grade above this elevation. Immediately below the 580 m asl, the quartz bearing zones appear to broaden into wider, lower grades zones and may lack a higher-grade center, before thinning at depth. Silver appears to have an uneven distribution throughout the mineralized interval but, in general, highest-grade silver is associated with higher-grade gold.

Drilling has now moved to the Tahonitas road system to better target extensions of the Zapote South mineralized system.

Management Additions and Options Grant

The Company has engaged a full time Los Reyes project manager and a new corporate secretary. Mr. Larry Segerstrom, M.Sc., M.B.A., is a senior mining professional with extensive technical, operational, and business experience, including exploration, mine geology, project management and operations. Mr. Segerstrom served as Chief Operating Officer of Paramount Gold and Silver Corp. and managed the discovery and development of their epithermal gold and silver project in Mexico. He also worked for Freeport-McMoRan Inc., Newmont Corporation, and Phelps Dodge Corporation.

Ms. Dianne Szigety has joined the Company as Corporate Secretary. Ms. Szigety is a Chartered Secretary and Fellow of the Chartered Governance Institute of Canada. She is a corporate governance specialist with strong organizational abilities and over 25 years' experience in public company administration.

In connection with these management additions, and pursuant to its Stock Option Plan, Prime granted stock options to key employees to purchase an aggregate of 700,000 common shares of the Company for a period of 5 years from the grant date. 100,000 of the options will vest 1/3 immediately as of the date of grant; 1/3 six months after the date of the grant and 1/3 twelve months after the date of the grant. 600,000 options will vest 1/3 nine months after the date of grant; 1/3 eighteen months after the date of the grant and 1/3 twenty-four months after the date of the grant. This stock option grant is subject to acceptance by the TSX Venture Exchange.

About Prime Mining

Prime Mining, a member of the TSX Venture 50, is an ideal mix of successful mining executives, strong capital markets personnel and experienced local operators who have united to build a low cost, near-term gold producer at the historically productive Los Reyes project in Mexico. Prime Mining has a well-planned capital structure with significant team and insider ownership.

Contact:

Daniel Kunz

Tel: 1-208-926-6379

Email: daniel@primeminingcorp.ca

Forward Looking Information

Information set forth in this document may include forward-looking statements. While these statements reflect management's current plans, projections, and intents, by their nature, forward-looking statements are subject to numerous risks and uncertainties, some of which are beyond the control of the Company. Readers are cautioned that the assumptions used in the preparation of such information, although considered reasonable at the time of preparation, may prove to be imprecise and, as such, undue reliance should not be placed on these forward-looking statements. There is no assurance the transactions noted above will be completed on the terms as contemplated, or at all. The Company's actual results, programs, activities, and financial position could differ materially from those expressed in or implied by these forward-looking statements.

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