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Sierra Madre Files Ni 43-101 Technical Report ON Updated Mineral Resource Estimate FOR LA Guitarra

Resource Estimates Technical Reports (NI 43-101)

SIERRA MADRE FILES NI 43-101 TECHNICAL REPORT ON UPDATED MINERAL RESOURCE ESTIMATE FOR

LA GUITARRA

Vancouver, British Columbia – December 15, 2023 – Sierra Madre Gold and Silver Ltd. (TSXV: SM, OTCQX: SMDRF)

("Sierra Madre" or the "Company") has filed a technical report, prepared in accordance with the National

Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”) for its La Guitarra silver-gold mine

and the Temascaltepec mining district (“La Guitarra”) in Estado de Mexico, Mexico. Sierra Madre previously

released the results of the Mineral Resource Estimate (the “MRE”) on November 1, 2023. The technical report is

available on SEDAR+ under the Company’s profile at www.sedarplus.com and on the Company’s website at

www.sierramadregoldandsilver.com TechSer Mining Consultants Ltd. (“TechSer”) of Vancouver B.C. prepared the

Mineral Resource Estimate, David Thomas, P.Geo. and QP Geology and Cristian Garcia, P.Eng. and QP Mining.

Key Highlights of the MRE include:

• 373% increase to 27.2M oz Silver Equivalent (“AgEq”) Indicated Resource

• 204% increase to 20.2M oz AgEq Inferred Resource

The following tabulates the La Guitarra estimated Mineral Resources.

Table 1: Summary La Guitarra 2023 Mineral Resource Estimate, David G. Thomas P. Geo (Effective Date: October

24, 2023)

Class Tonnes AgEq

(g/t)

Ag

(g/t)

Au

(g/t) AgEq Ozs Ag Ozs Au Ozs

Indicated 3,842,000 220 146 0.96 27,207,000 18,073,000 118,000

Inferred 4,105,000 153 113 0.52 20,199,000 14,937,000 68,000

1. See notes following Table 3

The following tabulates the Mineral Resource Estimates by Classification and Area.

Table 2: Indicated Mineral Resource Estimate

Area Tonnes AgEq

(g/t)

Ag

(g/t)

Au

(g/t) AgEq Ozs Ag Ozs Au Ozs

Nazareno 310,000 257 215 0.55 2,564,000 2,141,000 5,000

Coloso 432,000 346 221 1.61 4,806,000 3,071,000 22,000

Guitarra 1,649,000 220 123 1.25 11,664,000 6,544,000 66,000

Sub-Total 2,391,000 248 153 1.22 19,034,000 11,756,000 93,000

Los Angeles 690,000 177 109 0.87 3,919,000 2,419,000 19,000

Mina De Agua 761,000 174 159 0.19 4,255,000 3,899,000 5,000

Total Indicated 3,842,000 220 146 0.96 27,208,000 18,074,000 117,000

Table 3: Inferred Mineral Resource Estimate

Area Tonnes AgEq

(g/t)

Ag

(g/t)

Au

(g/t) AgEq Ozs Ag Ozs Au Ozs

Nazareno 754,000 252 229 0.29 6,096,000 5,554,000 7,000

Coloso 374,000 317 213 1.34 3,810,000 2,565,000 16,000

Guitarra 293,000 180 113 0.87 1,690,000 1,059,000 8,000

Sub-Total 1,421,000 254 201 0.68 11,596,000 9,178,000 31,000

Los Angeles 66,000 157 76 1.05 333,000 161,000 2,000

Mina De Agua 545,000 188 178 0.13 3,301,000 3,120,000 2,000

Subtotal UG Mine 2,032,000 233 191 0.55 15,230,000 12,459,000 35,000

Inferred Tailings 2,073,000 75 37 0.48 4,968,000 2,475,000 32,000

Total Inferred 4,105,000 153 113 0.52 20,198,000 14,934,000 67,000

(1) Notes for Mineral Resource Estimate:

1. Canadian Institute of Mining Metallurgy and Petroleum ("CIM") definition standards were followed for the resource estimate.

2. The 2023 resource models used nominal cutoff grades which are based on mining and milling costs of US$50 for cut and fill mining, US$38

per tonne for long-hole,

3. A net payable recovery of 70% (historical plant recovery plus an allowance for smelter deductions, refining costs, and concentr ate

transportation)

4. Silver price of US$22 and a gold price of $1700 and a Gold Silver Ration of 77.27:1.

5. Assays were capped at 825 g/t for silver and 6.55 g/t for gold

6. Variable cut-off by deposit

a. Nazareno and Coloso - Block Model 135 AgEq cut-off grade (COG) and a 1 m Minimum True Thickness

b. Guitarra - Polygonals Estimates 135 g/t AgEq COG and a 1 m Minimum Horizontal Width

c. Los Angeles - Block Model Long Hole Mining 90 g/t AgEq COG

d. Mina De Agua - East District Polygonal Estimate 135 g/t AgEq COG or 90 g/t AgEq COG and > 2 m Horizontal Width

e. The tailings used a 30 g/t AgEq COG.

7. Mineral Resources that are not mineral reserves do not have economic viability. Numbers may not add due to rounding.

8. Numbers may not add due to rounding.

9. The estimate of mineral resources may be materially affected by: metal prices and exchange rate assumptions; changes in local

interpretations of mineralization geometry and continuity; changes to grade capping, density and domain assignments; changes to

geotechnical, mining and metallurgical recovery assumptions; ability to maintain environmental and other regulatory permits and ability

to maintain the social license to operate

10. The 2023 resource estimate is prepared by David Thomas P.Geo. and Q.P. and Cristian Garcia P.Eng. and QP, of TechSer in accordance with

National Instrument 43 -101 Standards of Disclosure for Mineral Projects. David Thomas and Cristian Garcia are independent qualified

person ("QP’s") as defined by National Instrumen t 43 -101. A full technical report, has been prepared in accordance with National

Instrument 43-101 Standards of Disclosure for Mineral Projects, and has been filed and is available under the Company’s SEDAR+ profile at

www.sedarplus.com within 45 days of this news release.

Qualified Person

Mr. Gregory Smith, P. Geo, Director of Sierra Madre, is a Qualified Person as defined by NI 43-101, and

has reviewed and approved the technical data and information contained in this news release. Mr.

Smith has verified the technical and scientific data disclosed herein.

About Sierra Madre

Sierra Madre Gold & Silver (TSX.V: SM, OTCQX: SMDRF) is a precious metals development and

exploration company, focused on evaluating the potential of restarting the La Guitarra Mine in the

Temascaltepec mining district, Mexico, and the exploration and development of its Tepic and La Tigra

properties in Nayarit, Mexico. The La Guitarra Mine is a permitted, past-producing underground mine

which includes a 500 t/d processing facility that operated until mid-2018.

The +2,600 ha Tepic Project hosts low-sulphidation epithermal gold and silver mineralization with an

existing historic resource. La Tigra, located 148 km north of Tepic, has been mined historically; Sierra

Madre´s maiden 2022 drill program at the site intercepted shallow mineralization.

Sierra Madre´s management has played key roles for managing exploration and development of more

than 22Moz gold and 600Moz silver in combined reserves and resources. Sierra Madre´s team of

professionals has collectively raised over $1B for mining companies.

On behalf of the board of directors of Sierra Madre Gold and Silver Ltd.,

"Alexander Langer"

Alexander Langer

President, Chief Executive Officer and Director

1-604-765-1604

Contact:

[email protected]

Cautionary Note

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 news

release.

This press release contains "forward-looking information" and "forward-looking statements" within the

meaning of applicable securities legislation. The forward-looking statements herein are made as of the

date of this press release only, and the Company does not assume any obligation to update or revise

them to reflect new information, estimates or opinions, future events or results or otherwise, except as

required by applicable law. Often, but not always, forward-looking statements can be identified by the

use of words such as "plans", "expects", "is expected", "budgets", "scheduled", "estimates", "forecasts",

"predicts", "projects", "intends", "targets", "aims", "anticipates" or "believes" or variations (including

negative variations) of such words and phrases or may be identified by statements to the effect that

certain actions "may", "could", "should", "would", "might" or "will" be taken, occur or be achieved.

Forward-looking information in this press release includes, but is not limited to, statements with respect

to the completion of the Transaction on the terms set out in the definitive agreement (or at all) and the

ability of the Company to obtain requisite corporate and regulatory approvals for the Transaction,

including but not limited to the approval of the Exchange, Mexican antitrust approval and other

governmental approvals as currently anticipated.

In making the forward-looking statements included in this news release, the Company has applied

several material assumptions, including that the Company will be able to receive all required regulatory

approvals by the timelines currently anticipated (or at all); and that the Company will be able to

complete the Transaction on the terms of the definitive agreement. Forward-looking statements and

information are subject to various known and unknown risks and uncertainties, many of which are

beyond the ability of the Company to control or predict, that may cause the Company´s actual results,

performance or achievements to be materially different from those expressed or implied thereby, and are

developed based on assumptions about such risks, uncertainties and other factors set out herein,

including, but not limited to, the risk that the Company is not able to complete Transaction on the terms

set out in the definitive agreement (or at all) and the risk that the Company is unable to obtain requisite

corporate and regulatory approvals, including but not limited to the approval of the TSX Venture

Exchange, the Mexican antitrust approval and governmental approval as currently anticipated.

Such forward-looking information represents management´s best judgment based on information

currently available. No forward-looking statement can be guaranteed and actual future results may vary

materially. Accordingly, readers are advised not to place undue reliance on forward-looking statements

or information.

SOURCE: Sierra Madre Gold and Silver