McEwen Mining Inc. Page 1 2024 Drilling Campaign at Grey Fox Finishes Strong: 24GF-1520: 17.7 g/t Gold over 8.0 m 24GF-1522: 55.6 g/t Gold over 0.6 m 24GF-1520: 9.8 g/t Gold over 2.1 m 2025 Drilling Campaign Is Underway. First Results from Gibson Zone:
McEwen Mining Inc. Page 1
2024 Drilling Campaign at Grey Fox Finishes Strong:
24GF-1520: 17.7 g/t Gold over 8.0 m
24GF-1522: 55.6 g/t Gold over 0.6 m
24GF-1520: 9.8 g/t Gold over 2.1 m
2025 Drilling Campaign Is Underway. First Results from Gibson Zone:
25GF-1525: 12.9 g/t Gold over 4.3 m and 15.3 g/t Gold over 2.7 m
Geophysics Survey Now Complete, Data Interpretation in Progress
TORONTO, Feb. 27th, 2025 (GLOBE NEWSWIRE) -- McEwen Mining Inc. (NYSE: MUX) (TSX: MUX) is pleased
to announce that exploration at the Grey Fox Deposit, part of the Fox Complex, successfully delivered in 2024
a large increase in our gold resources. Early results from the 2025 program are also most encouraging. The 2025
exploration budget for the Fox Complex is US$9.7 million, including 68,500 meters of diamond drilling.
All assay intervals are expressed in true widths (TW) unless otherwise stated.
Late 2024 & Early 2025 Highlights:
● Gibson Zone drilling: Hole 24GF-1520 returned 17.7 g/t gold (Au) over 8.0 m, while the first results received
for the 2025 campaign returned 12.9 g/t gold over 4.3 m and 15.3 g/t gold over 2.7 m (25GF-1525).
● Multi-pronged approach for exploration at the Grey Fox Horizon and the Black Fox Horizon, which includes
drilling, geophysics and additional geological modelling. The Grey Fox Horizon has a cluster of 173 lenses of
epithermal gold mineralization and demonstrates good continuity within the lenses.
● An updated resource estimate for Grey Fox was recently published (see February 4, 2025 press release), with
an Indicated resource of 1,538,000 ounces of gold at a grade of 3.64 g/t gold and an Inferred resource of
458,000 ounces of gold at a grade of 3.30 g/t gold, using a cut-off grade of 1.60 g/t gold.
● A principal focus of the 2025 drilling campaign will be the expansion of the current resource, including at the
Gibson Zone, where 23 additional epithermal lenses were discovered near the historical Gibson ramp.
● The Whiskey Jack Zone is located approximately 350 meters from the entrance to the Gibson ramp. This zone
has the highest Indicated grade of 5.7 g/t gold and greatest average true width of 5-7 meters for the entire
cluster of epithermal lenses within the Grey Fox Horizon.
● Exploration will begin soon within the Black Fox Horizon for potential orogenic gold discoveries. The Black
Fox Horizon is bounded by the Porcupine-Destor fault, and a subordinate structure known as the A1 Fault. It
is a highly prospective corridor for exploration, which has had minimal drilling to the south-east of the orogenic-
type gold deposit seen at the Black Fox Mine.
● Ground-based geophysical surveys - Direct Current Induced Polarization (DCIP) and Magnetotelluric (MT)
have been recently completed. Preliminary results are being used to guide current drill hole targeting.
Rob McEwen, Chairman and Chief Owner said, “During my time leading Goldcorp, we transformed our
Red Lake Mine, by challenging the accepted geological model and committing to a large exploration
program. We drilled deep and into the hanging wall and the results were outstanding. We hit the bonanza-
grade portion of the orogenic gold system where the outside consensus said it would not be. It was
McEwen Mining Inc. Page 2
a gamechanger for the company, reinforcing my steadfast belief in the critical importance of exploration
and the explosive improvement in share value it can deliver.
Today, we are at an exciting juncture with our exploration at the Fox Complex. We are focused on
exploration drilling which is increasing our gold resources at a time when gold is making record highs
against every fiat currency, including the US dollar. For a higher cost miner such as us, these two
developments should drive a significant improvement in our operating profit margins.
The fundamentals supporting the continued strong demand for gold from central bankers and, particularly,
Eastern investors are primarily excessive debt and the erosion of fiat currencies’ purchasing power.
I believe strongly that the outlook for gold is very positive and that now is a time to be aggressively
building our gold resource base and annual gold production.”
Table 1 below is a list of important new and previously released results that are highlighted throughout this press
release.
Table 1. Grey Fox Drill Results
HOLE-ID
FROM
(m)
TO
(m)
Core Length
(CL) (m)
True Width
(TW) (m)
Grade
(Au g/t)
GxM TW
25GF-1525 117.0 123.0 6.0 4.3 12.9 55.6
25GF-1525 179.9 183.0 3.1 2.7 15.3 40.9
24GF-1522 43.4 44.1 0.7 0.5 17.1 8.6
24GF-1522 92.3 93.0 0.7 0.6 55.6 31.6
24GF-1521 39.9 43.7 3.8 3.1 4.9 15.2
24GF-1520 111.9 115.0 3.1 2.1 9.8 20.5
24GF-1520 337.3 342.0 4.7 3.4 2.3 7.7
24GF-1520 447.2 458.1 10.9 8.0 17.7 140.8
24GF-1519 90.3 91.5 1.2 1.0 18.0 17.2
24GF-1519 227.0 231.2 4.2 3.0 3.9 11.7
24GF-1513* 442.0 450.0 8.0 6.0 11.2 67.0
24GF-1507* 22.0 31.0 9.0 6.4 1.9 11.9
24GF-1507* 211.8 220.2 8.4 4.6 1.9 8.6
24GF-1476* 340.0 351.0 11.0 7.1 2.0 14.5
24GF-1475* 92.0 100.0 8.0 5.9 5.2 30.7
24GF-1474* 120.0 120.8 0.8 0.5 54.6 28.5
24GF-1401* 100.0 109.0 9.0 6.2 2.2 13.7
24GF-1399* 45.0 47.1 2.1 0.9 9.6 8.7
24GF-1397* 151.0 157.0 6.0 3.4 17.4 58.5
22GF-1365* 144.9 157.1 12.2 6.2 13.1 80.8
22GF-1363* 442.4 447.4 5.0 3.4 15.5 52.7
21GF-1333* 378.4 403.6 25.2 8.4 4.8 40.0
GF14-869** 251.9 258.0 6.1 3.3 25.5 84.8
GF08-15* 20.9 24.8 4.0 - 8.5 -
Including 24.2 24.8 0.6 - 52.0 -
21GF-1352* 431.0 432.0 1.0 - 27.5 -
19GF-1321* 459.0 460.1 1.1 - 15.4 -
19GF-1272* 350.0 351.0 1.0 - 15.3 -
Notes: *Denotes previously released results. **Denotes historical results. Numbers may not sum due to rounding. Drill results are uncapped.
McEwen Mining Inc. Page 3
Discussion of the 2025 Drill Campaign
As shown in Figure 1 below, the Grey Fox Deposit is comprised of six zones - Whiskey-Jack, Gibson, Contact,
147, 147NE and Grey Fox South (GFS) - denoted by yellow stars. These zones are located at the Southern end
of Fox Complex’s Eastern Property, while the Black Fox and Froome Mines are at the northern end.
Figure 1. Fox Complex – Plan Surface Geology Map of the Eastern Property Including Black Fox, Froome
and Grey Fox
McEwen Mining Inc. Page 4
The updated resource estimate for Grey Fox, released on February 4th, 2025, outlined over 1,500,000 ounces of
Indicated gold mineralization and more than 450,000 ounces of Inferred gold mineralization. Within this
resource, 290,000 ounces of Indicated gold mineralization and 245,000 ounces of Inferred gold mineralization
are from the Gibson Zone. The new epithermal lenses of mineralization for the updated resource can be seen
in red in Figure 2, including 23 new lenses in proximity to the historical Gibson Ramp. The high number of
stacked epithermal lenses in such a small area is indicative of a robust and significant mineralizing event.
Figure 2. Oblique View of the 173 Modeled Epithermal Lenses (Shown in Gold and Red) that Comprise the
Current Grey Fox Resource
The final results from the 2024 drilling campaign at Grey Fox (including at the Gibson Zone) have now been
received. Figure 3 is a composite plan map for a portion of the Gibson Zone, highlighting some of these results
while Figure 4 is a section view for the same area (A-A'). Many of these new intercepts are located within
100 meters of surface and in close proximity to the historical Gibson Ramp and represent near term potential
production. In addition, drillhole 24GF-1520 returned 17.7 g/t gold over 8.0 m about 280 meters below the
bottom of the historical Gibson Ramp and demonstrates the potential for resource growth in the deeper portions
of the Gibson Zone. Also noteworthy, the entrance to the historical Gibson Ramp is only 350 meters from the
Whiskey Jack Zone, which contains an Indicated resource of 116,000 ounces of gold with a grade of 5.7 g/t
gold.
McEwen Mining Inc. Page 5
Figure 3. Composite Plan View Map of the Ramp Area at the Gibson Zone, with Drill Intercepts
Continued…
McEwen Mining Inc. Page 6
Figure 4. Cross Section view (A-A') Cut from the Plan View Map in Figure 3, Showing Assay Results
An aggressive 25,000 meters drilling campaign now underway at the Gibson Zone is designed to continue
growing the resource in the area, especially North of the ramp, where there are indications of potentially
increasing grades and widths. Figure 5 is a zoomed-in plan view of the Northern portion of the Gibson Zone,
McEwen Mining Inc. Page 7
showing some of the higher grades and widths associated with that portion of Gibson, e.g., 21GF-1333:
4.8 g/t gold over 8.4 m and 22GF-1365: 13.1 g/t gold over 6.2 m. The first assay results received for the 2025
drilling program are from hole 25GF-1525, which graded 12.9 g/t gold over 4.3 m and 15.3 g/t gold over 2.7 m.
One possible explanation for the better grades and widths seen in this area of Gibson is that many of the
previously released intercepts are close to the contact between the Gibson syenite (the pink colored unit in
Figure 5) and sediments (the grey colored unit in Figure 5). The Gibson syenite may have been a ‘heat engine’
for some of the gold-bearing fluids which, coupled with rock competency contrasts between the syenite and
sediments would have made this area of Gibson ideal for robust gold deposition. In addition, some of the new
epithermal lenses identified at the Gibson Zone are between the ramp entrance and Whiskey Jack. As a result,
there is the opportunity to create underground development along mineralized lenses over to the Whiskey Jack
Zone.
The proposed drilling will continue to step to the North-West of the current resource area at Gibson to continue
to follow up on these good grades and widths.
Figure 5. Plan Map for the Gibson Ramp Area at Grey Fox
In terms of overall exploration, the Fox Complex can be subdivided into two distinct mineralized horizons (see
Figure 6). The first is known as the Grey Fox horizon which hosts the 173 epithermal lenses that make up the
Grey Fox deposit. This horizon appears to be bounded to the West by the Gibson-Kelore shear zone and to the
McEwen Mining Inc. Page 8
East by the A1 fault zone. The mineralization within this area is characterized by stacked epithermal vein systems,
with some present near surface (<25 m) down to vertical depths in excess of 700 m.
The second area of interest is the Black Fox horizon which is bounded by the Porcupine-Destor fault to the East
and the A1 fault to the West. This is the same horizon which hosts the Black Fox Mine located about 3 km North-
West of Grey Fox. Limited drilling into the Black Fox horizon in the Grey Fox area indicates the presence of
orogenic-related mineralization e.g., 21GF-1352: 27.5 g/t gold over 1.0 m Core Length (CL) and 19GF-1321:
15.4 g/t gold over 1.1 m CL. Drillhole GF08-15, which graded 8.5 g/t gold over 4.0 m CL, also appears to be
orogenic related, located near surface (<25 m) and has had limited follow-up, warranting further exploration.
Figure 6. Plan Map & Oblique Section View for the Eastern Properties of the Fox Complex
The Porcupine-Destor Fault and secondary structures (such as the A1 fault) near it are renowned sources of orogenic
gold mines. In the Timmins-Porcupine camp alone, approximately 79 million gold ounces have been produced over
a hundred plus years of mining history (report available here).
Our properties are located in the Abitibi mining region - Canada’s most important gold-producing region and one
of the largest gold districts worldwide. Key geological characteristics of this region include deep crustal faults,
such as the Porcupine-Destor Fault, which act as conduits to bring gold from deep within the Earth’s crust closer
to the surface. As the gold bearing fluids get closer to the surface, subordinate faults (such as the A1 Fault) are
important pathways for the fluids to make their way into, allowing for gold deposition into moderately to steeply
dipping vertical zones.