Rio Grande Resources Advances District-Scale Gold-Silver Target Definition at its Winston Project Through Structural Mapping of Multiple Vein Corridor Systems
Rio Grande Resources Advances District-Scale Gold-Silver
Target Definition at its Winston Project Through Structural
Mapping of Multiple Vein Corridor Systems
Phase 2 Sampling and Mapping Program Identifies Extensive Vein Corridors,
Structural Intersections, and Widespread Epithermal Textures Ahead of Planned
Phase 1 Drill Program
VANCOUVER, British Columbia – May 21, 2026 – Rio Grande Resources Ltd. (CSE: RGR, OTCQB:
RGRLF) (“Rio Grande” or “RIO” the “Company”), is pleased to announce completion of its Phase
2 field sampling and structural mapping program at the Winston Gold–Silver Project (“Winston”
or the “ Project”), located in the Black Range Mountains of Sierra County, New Mexico. The
program was completed by Dahrouge Geological Consulting USA Ltd. (“Dahrouge”) and included
extensive structural mapping and surface sampling designed to refine the Company’s geological
understanding of mineralized vein trends across the property ahead of its planned Phase 1 drill
program.
During the seven-day program conducted the second week of May 2026 (see News release May
06, 2026) , Dahrouge collected 75 rock chip samples and 5 channel samples, representing an
additional 16 individual samples, for a total of 91 individual samples submitted for analysis. The
program’s extensive structural mapping, represented by 307 new data points, has significantly
enhanced the Company’s understanding of mineralized vein trends and interpreted corridors
throughout the Winston claim block . The structural dataset includes mapped vein orientations,
mineralization characteristics, textural observations, and structural measurements are expected
to play an important role in refining and prioritizing drill targets for the Company’s planned Phase
1 drill program.
Highlights include:
• 91 individual samples collected, including rock chip and channel samples
• 307 new structural data points collected across multiple target areas
• Multiple steeply dipping vein corridors and structural intersections identified
• Mapping supports continuity of interpreted mineralized trends between Poverty Creek,
Highway 59, Ivanhoe–Emporia, and Little Granite.
• Epithermal quartz textures observed across several target areas, including bladed quartz,
drusy quartz, comb quartz, amethyst, colloform banding, and vuggy textures
Jason Barnard, CEO of Rio Grande Resources, commented: “This second phase field program has
significantly advanced our understanding of the Winston Project and further strengthened our
confidence in the scale of the mineralized system. The structural data collected by Dahrouge
has helped identify and refine sev eral priority target corridors that we believe have strong
potential. We are particularly encouraged by the increasing evidence that Winston may
represent a larger district-scale epithermal system and look forward to integrating the pending
assay results into our evolving drill targeting model in advance of our planned Phase 1 drill
program, as we continue advancing the Winston Project for the benefit of our Company and its
shareholders.”
The Company believes the completed field program has materially advanced its geological model
for the Winston Project . Multiple vein corridors appear to extend through key target areas,
including Poverty Creek, north of Highway 59, Ivanhoe–Emporia, and the Little Granite area. The
recognition of these potential continuities, combined with the newly collected structural dataset,
is expected to help refine targets where future drilling may test for vein intersections, continuity
along strike, and mineralization at depth (see Figure 1).
Figure 1: Property map showing 2026 sample points and vein trends. Vein lines are created using field data from December 2025 and May
2026 field programs
District Scale Potential Further Supported
Mapping completed to date increasingly supports the interpretation that Winston may represent
a connected, district-scale low-sulfidation epithermal gold -silver system rather than a series of
isolated vein occurrences . Multiple steeply dipping vein corridors, including vein swarms with
several structural intersection points were identified in this program . In low -sulfidation
epithermal systems, these structural intersections can represent favorable zones for enhanced
hydrothermal fluid flow, a key geological process associated with precious-metal deposition.
Throughout the property, textures typical of a low -sulfidation epithermal system, including
bladed quartz, drusy quartz, comb quartz, amethyst, colloform banding, and vuggy textures, were
identified within structurally controlled vein systems (see pictures 1 and 2). These observations
are consistent with the geological characteristics identified during the Company’s December 2025
field program and further support the interpretation of a large -scale epithermal gold -silver
system at Winston (See news release December 12, 2025).
In the Poverty Creek region, mapping identified a broad swarm of structurally controlled veins
extending from the northern portion of the claim block through Highway 59 and into the Poverty
Creek corridor. Several of these vein trends appear continuous acr oss multiple target areas and
are associated with historical workings and previously identified mineralized structures (see
Figure 2).
Figure 2: Structural trends of the Poverty Creek area with 2026 sample points. Vein lines are created using field data from December 2025
and May 2026 field programs
Structural measurements collected during the program also improved the Company’s
understanding of vein orientations and controls on mineralization within the Ivanhoe –Emporia
region.
Next Steps
Assay results from the completed sampling program are currently pending . Upon receipt , the
Company plans to integrate the assay results with the newly collected structural mapping data,
previously reported surface sampling results, and airborne geophysical interpretations to refine
and prioritize high-confidence drill targets ahead of the planned Phase 1 drill program.
Picture 3: In Situ quartz vein exposure exhibiting classic epithermal textures and mineral banding. Sample WIN-051226-14
The Company expects this integrated dataset to support drill targeting focused on structurally
favorable areas, including vein intersections, interpreted mineralized corridors, and zones
demonstrating strong epithermal textures (see picture 3) and structural continuity across the
Winston Project.
Corporate Secretary Appointment
Rio Grande Resources is also pleased to announce the appointment of Andrew Brown as
Corporate Secretary, effective May 25, 2026. Mr. Brown has over thirteen years of experience in
the public markets and has served as an executive officer of both TSX Venture Exchange and
Canadian Securities Exchange listed issuers. Mr. Brown is the founder of Ardent Corporate
Services Inc. and has served as President of a Vancouver -based corporate services firm. He
previously served as Vice President, Corporate Affairs and Corporate Secretary of a TSX Venture
Exchange listed issuer. His areas of specialization include business development, corporate
governance, executive management, project management, and public company administration.
Rio looks forward to benefiting from Mr. Brown’s extensive experience and leadership as he
assumes the role.
Qualified Person
The scientific and technical information contained in this news release has been reviewed and
approved by Mr. Jacob Anderson CPG, MAusIMM, a Qualified Person as defined under National
Instrument 43-101. Mr. Anderson is independent of Rio Grande Resources.
The Qualified Person has reviewed the sampling procedures, analytical methods, and results
disclosed herein and is satisfied that the information has been accurately presented. Verification
included a review of field procedures, sample locations, and consistency with historical records.
About Rio Grande Resources
Rio Grande Resources (CSE:RGR) (OTCQB: RGRLF) is a burgeoning mineral exploration company
focused on unlocking the high -grade gold and silver potential within its 3,000 -acre drill-ready
property in the Black Range of Sierra County, New Mexico. The company holds 100% interest in
the Winston project group, which includes the 2 patented historic Ivanhoe & Emporia Claims, and
Little Granite mines, all known for their past production of high-grade precious metals. Rio Grande
Resources is led by a team of experienced professionals with expertise in mineral exploration and
development, who are targeting large-scale precious metal discoveries within the property’s well-
documented low-sulfidation epithermal setting.
To view the company fact sheet and corporate presentation, please visit our website
at www.riogranderesources.ca
Contact and Information
Company
Jason Barnard, CEO and Director
(604) 767-6598
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Forward-Looking Statements
Except for the statements of historical fact contained herein, the information presented in this
news release and oral statements made from time to time by representatives of the Company are
or may constitute “forward-looking statements” as such term is used in applicable United States
and Canadian laws and including, without limitation, within the meaning of the Private Securities
Litigation Reform Act of 1995, for which the Company claims the protection of the safe harbor for
forward-looking statements. Such forward-looking statements and forward-looking information
include, but are not limited to, the proposed benefits of the Arrangement. These statements
relate to analyses and other information that are based on forecasts of future results, estimates
of amounts not yet determinable and assumptions of management. Any other statements that
express or involve discussions with respect to predictions, expectations, beliefs, plans,
projections, objectives, assumptions or future events or performance (often, but not always,
using words or phrases such as “expects” or “does not expect,” “is expected,” “anticipates” or
“does not anticipate,” “plans,” “estimates” or “intends,” or stating that certain actions, events or
results “may,” “could,” “would,” “might” or “wi ll” be taken, occur or be achieved) are not
statements of historical fact and should be viewed as forward-looking statements. The Company
cautions that the identification of structural features or geophysical anomalies does not
necessarily indicate the presence of economic mineralization, and there can be no assurance that
the Company’s geological interpretation or exploration objectives will result in a discovery. Such
forward-looking statements involve known and unknown risks, uncertainties and other factors
which may cause the actual results, performance or achievements of the Company to be
materially different from any future results, performance or achievements expressed or implied
by such forward -looking statements. Such risks and other factors includ e, among others, the
availability of capital to fund programs and the resulting dilution caused by the raising of capital
through the sale of shares, continuity of agreements with third parties, the satisfaction of the
conditions to the Arrangement, risks and uncertainties associated with the environment and
delays in obtaining governmental approvals, permits or financing. Although the Company has
attempted to identify important factors that could cause actual actions, events or results to differ