Mr. Darren Hall reports

CALIBRE CONTINUES TO INTERCEPT HIGH-GRADE GOLD MINERALIZATION AT ITS EASTERN BOROSI MINE COMPLEX; DRILLING INTERSECTS INCLUDE 13.24 G/T GOLD OVER 5.8 METRES AND 11.62 G/T GOLD OVER 3.8 METRES

Calibre Mining Corp. has released drill results from its 2024 resource conversion and expansion program within the Guapinol open-pit area on the company's 176-square-kilometre Eastern Borosi mine complex in northeastern Nicaragua. This prolific land package sits adjacent to a larger, 100-per-cent-owned, 7,281-square-kilometre Atlantic mineral concession package which has high potential for the discovery of both epithermal gold-silver and porphyry copper-gold systems.

Gold highlights from the Eastern Borosi drill program:

• 13.24 grams per tonne (g/t) gold (Au) over 5.8 metres estimated true width (ETW), including 18.52 g/t Au over four metres ETW, in hole GP-24-182;
• 9.24 g/t Au over 6.2 metres ETW, including 17.45 g/t Au over 3.1 metres ETW, in hole GP-24-189;
• 11.62 g/t Au over 3.8 metres, ETW including 22.36 g/t Au over 1.9 metres, ETW in hole GP-24-187;
• 9.25 g/t Au over 1.6 metres EW, including 12.70 g/t Au over 1.1 metres ETW, in hole GP-24-179;
• 7.81 g/t Au over 8.6 metres ETW, including 16.61 g/t Au over 3.7 metres ETW, in hole GP-24-181;
• 3.37 g/t Au over 2.9 metres ETW, including 6.13 g/t Au over 1.4 metres ETW and 3.31 g/t Au over 7.3 metres ETW, including 8.15 g/t Au over 1.6 metres ETW and 6.67 g/t Au over 0.8 metre ETW, in hole GP-24-178A;
• 5.01 g/t Au over 4.5 metres ETW, including 8.59 g/t Au over 2.5 metres ETW, in hole GP-24-186.

Darren Hall, president and chief executive officer of Calibre, stated: "Today's drill results from Eastern Borosi confirm that significant high-grade gold mineralization exists outside of the present deposit area surrounding the Guapinol operation, reinforcing the potential for mine life extension. These drill results build upon the high-grade gold mineralization results reported earlier this year (see news release dated April 15, 2024) confirming the significant mineral endowment of the district, as well as the high potential for discovery and resource expansion within the entire 176-square-kilometre Eastern Borosi land package."

Quality assurance/quality control

Calibre maintains a quality assurance/quality control (QA/QC) program for all its exploration projects using industry best practices. Key elements of the QA/QC program include verifiable chain of custody for samples, regular insertion of certified reference standards and blanks, and duplicate check assays. Drill core is halved and shipped in sealed bags to Bureau Veritas in Managua, Nicaragua, an independent analytical services provider with global certifications for quality management systems ISO 9001:2008, environmental management: ISO14001, and safety management OH SAS 18001 and AS4801. Prior to analysis, samples are prepared at Veritas's Managua facility and then shipped to its analytical facility in Vancouver, Canada. Gold analyses are routinely performed through fire assay/AA (atomic absorption) finish methods. For greater precision of high-grade material, samples assaying 10 g/t Au or higher are re-assayed by fire assay with a gravimetric finish. Analyses for silver and other elements of interest are performed through induction coupled plasma (ICP).

Qualified person

The scientific and technical information contained in this news release was approved by David Schonfeldt, PGeo, Calibre Mining's corporate chief geologist and a qualified person under National Instrument 43-101.

About Calibre Mining Corp.

Calibre is a Canadian-listed, Americas focused, growing mid-tier gold producer with a strong pipeline of development and exploration opportunities across Newfoundland and Labrador in Canada, Nevada and Washington in the United States, and Nicaragua.

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