Grande Portage Resources: Advancing the High-grade Herbert Gold Project in Alaska

Scout Drilling Discovered the Extension of the High-grade Merten Vein Creating an Opportunity to Expand the Dpb Resource up to 1,200 Metres to the East

SCOUT PROGRAM HIGHLIGHTS:

• Assay results from the Company's reverse circulation Scout Drill Program (see March 31, 2025 news) returned significant gold & silver values in 7 drillholes that successfully expanded the footprint of mineralization up to 1,200 metres from the east of the existing DPB resource toward the historic Ohio mine;

 

• These intercepts cover a new zone of silver and gold interpreted to be the outer ring structure of the Fraction caldera, and are not included in the 2024 resource;

 

• A fully funded 15 drillhole program totalling up to 5,000 metres is underway; and

 

• Results from this program will be incorporated into an updated Mineral Resource Estimate in Q1, 2026.

 

Vancouver, British Columbia--(Newsfile Corp. - July 21, 2025) - Blackrock Silver Corp. (TSXV: BRC,OTC:BKRRF) (OTCQX: BKRRF) (FSE: AHZ0) ("Blackrock" or the "Company") announces commencement of a fully-funded expansion drill program ("Expansion Program") to follow up on the successful Scout Drilling campaign that expanded the DPB South zone 1,200 metres in an easterly direction on its 100% owned Tonopah West project located in Nye and Esmeralda Counties, Nevada, United States.

The Expansion Program will utilize one Reverse Circulation (RC) drill overseen by Legacy Drilling and two core drill rigs operated by Alloy Drilling to complete 2,450 metres (8,000 ft) of RC precollars and 2,550 metres (8,400 ft) of core tails across 15 drillholes targeting the Eastern Expansion zone between the DPB resource area and the eastern extent of the project. Drilling is anticipated to be completed in October with assay results expected through year end.

Andrew Pollard, Blackrock's President and CEO, stated, "With drills now turning on this fully financed program, we're stepping out across a 1.2-kilometre corridor with strong potential to significantly expand our mineral inventory at Tonopah West. Scout drilling confirmed the eastern extension of the high-grade Merten vein well beyond the current resource boundary, returning standout grades including 2,063 grams per tonne (g/t) silver equivalent (AgEq) (1,198 g/t silver (Ag) and 9.6 g/t gold (Au)) over 1.52 metres, and 952 g/t AgEq (10 g/t Ag and 10.5 g/t Au) over 4.57 metres. This newly defined zone, situated along the outer ring structure of the Fraction caldera, lies entirely outside our 2024 resource and presents an opportunity to quickly and meaningfully grow the scale of the project. Results from this program are expected to underpin a resource update in Q1 2026. The Company remains on track to deliver a separate resource update in Q3 2025 that will incorporate all results from the recently completed M&I conversion program."

As announced on March 31, 2025, the Company discovered the 1,200 metre eastern extension zone representing the continuation of the outer-ring structure or Fraction caldera margin from DPB South to the historic Ohio mine. The Scout Drilling showed the Merten vein extends eastward and is arched and dips southward. This orientation suggests multiple ring structures associated with the Fraction caldera running across Tonopah West. An inner structure hosting the Victor and DPB North (Denver and Paymaster) resources, and an outer, more southern, ring structure hosting DPB South (Merten and Bermuda) and the NW Stepout resources (See Figure 1). The arching geometry of the Merten vein is similar to that described from the historic Ohio vein which was 15 metres thick when mined in the early 1900s¹. Given the geometry and location, the Merten is potentially the extension of the Ohio vein. Table 1 summarizes the Scout Drilling assay results above 150 g/t AgEq.

Table 1: Scout Drilling Program results above 150 g/t AgEq

TW25-133 returned significant silver and gold with values starting at 309-metres grading 10.46 g/t gold and 10.6 g/t silver over 4.57 metres (952 g/t AgEq), and show mineralization extends along the Merten vein for 540 meters to the east-southeast of the main DPB South resource. With the inclusion of TW25-128 which returned 9.6 g/t gold and 1198 g/t silver over 1.5-metres (2,063 g/t AgEq), the zone could be up to 1,200-metres in length.

The mineralized zone traced by these assay results is new and not included in the 2024 resource. These results could have a substantive impact on the future resource estimate.

Figure 1: Tonopah West expansion potential

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Figure 2: Drillhole location map with cross section line at location 478540E

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Figure 3: Geologic cross section along 478540E

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Quality Assurance/ Quality Control

All sampling is conducted under the supervision of the Company's project geologists, and a strict chain of custody from the project to the sample preparation facility is implemented and monitored. The RC samples are hauled from the project site to a secure and fenced facility in Tonopah, Nevada, where they are loaded on to American Assay Laboratory's (AAL) flat-bed truck and delivered to AAL's facility in Sparks, Nevada. A sample submittal sheet is delivered to AAL personnel who organize and process the sample intervals pursuant to the Company's instructions.

The RC samples are lined out at the lab and logged into AAL's system. The samples are dried, crushed to 85% passing 10 mesh (2mm) and a 250-gram sub-sample split is collected and pulverized to 200 mesh (74 micron) in a ring and puck pulverizer. Then the pulverized material is digested and analyzed for gold using fire assay fusion and an Induced Coupled Plasma (ICP) finish on a 30-gram assay split (FA-PB30-ICP). Silver is determined using five-acid digestion and ICP analysis (ICP-5AM48). Over limits for gold and silver are determined using a gravimetric finish (GRAVAU30 and GRAVAG30). Data verification of the assay and analytical results are completed to ensure accurate and verifiable results. Blackrock personnel insert a blind prep blank, lab blank or a certified reference material approximately every 15th to 20th sample.

Qualified Persons

Blackrock's exploration activities at Tonopah West are conducted and supervised by Mr. William Howald, Executive Chairman of Blackrock. Mr. William Howald, AIPG Certified Professional Geologist #11041, is a Qualified Person as defined under National Instrument 43-101 - Standards of Disclosure for Mineral Projects. He has reviewed and approved the contents of this news release.

About Blackrock Silver Corp.

Backed by gold and silver ounces in the ground, Blackrock is a junior precious metal focused exploration and development company driven to add shareholder value. Anchored by a seasoned Board of Directors, the Company is focused on its 100% controlled Nevada portfolio of properties consisting of low-sulphidation, epithermal gold and silver mineralization located along the established Northern Nevada Rift in north-central Nevada and the Walker Lane trend in western Nevada.

Additional information on Blackrock Silver Corp. can be found on its website at www.blackrocksilver.com and by reviewing its profile on SEDAR at www.sedarplus.ca.

Cautionary Note Regarding Forward-Looking Statements and Information

This news release contains "forward-looking statements" and "forward-looking information" (collectively, "forward-looking statements") within the meaning of Canadian and United States securities legislation, including the United States Private Securities Litigation Reform Act of 1995. All statements, other than statements of historical fact, are forward-looking statements. Forward-looking statements in this news release relate to, among other things: the Company's strategic plans; the timing of and successful completion of the Company's Expansion Program at Tonopah West and the anticipated objectives and results therefrom; timing and estimates of mineral resource quantities and qualities; timing of updated resource estimates; estimates of mineralization from drilling; geological information projected from sampling results; and the potential quantities and grades of the target zones.

These forward-looking statements reflect the Company's current views with respect to future events and are necessarily based upon a number of assumptions that, while considered reasonable by the Company, are inherently subject to significant operational, business, economic and regulatory uncertainties and contingencies. These assumptions include, among other things: conditions in general economic and financial markets; accuracy of assay results; geological interpretations from drilling results, timing and amount of capital expenditures; performance of available laboratory and other related services; future operating costs; the historical basis for current estimates of potential quantities and grades of target zones; the availability of skilled labour and no labour related disruptions at any of the Company's operations; no unplanned delays or interruptions in scheduled activities; all necessary permits, licenses and regulatory approvals for operations are received in a timely manner; the ability to secure and maintain title and ownership to properties and the surface rights necessary for operations; and the Company's ability to comply with environmental, health and safety laws. The foregoing list of assumptions is not exhaustive.

The Company cautions the reader that forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause actual results and developments to differ materially from those expressed or implied by such forward-looking statements contained in this news release and the Company has made assumptions and estimates based on or related to many of these factors. Such factors include, without limitation: the timing and content of work programs; results of exploration activities and development of mineral properties; the interpretation and uncertainties of drilling results and other geological data; receipt, maintenance and security of permits and mineral property titles; environmental and other regulatory risks; project costs overruns or unanticipated costs and expenses; availability of funds; failure to delineate potential quantities and grades of the target zones based on historical data; general market and industry conditions; and those factors identified under the caption "Risks Factors" in the Company's most recent Annual Information Form.

Forward-looking statements are based on the expectations and opinions of the Company's management on the date the statements are made. The assumptions used in the preparation of such statements, although considered reasonable at the time of preparation, may prove to be imprecise and, as such, readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date the statements were made. The Company undertakes no obligation to update or revise any forward-looking statements included in this news release if these beliefs, estimates and opinions or other circumstances should change, except as otherwise required by applicable law.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.