Mr. Adam Travis reports

COAST COPPER ANNOUNCES HIGH-GRADE GOLD-COPPER MINERAL RESOURCE ESTIMATE FOR MERRY WIDOW OPEN PIT, EMPIRE MINE, BC

Coast Copper Corp. has released a National Instrument 43-101 mineral resource estimate for the gold-copper Merry Widow open pit located at its optioned Empire mine property. The 2023 MRE updates and improves the 2008 MRE published by Grande Portage Resources Ltd. and should be considered Coast Copper's first proof of concept with the results feeding into a scoping study for a hub and spoke processing facility previously announced by Coast Copper (see news release March 21, 2023).

Highlights from Coast Copper's 2023 MRE include:

• Geological proof of concept that copper-gold-magnetite mineralization is structurally controlled at intersections of both thrust and high-angle faults, in addition to dike margins.
• Inferred mineral resource estimate of 81,322 ounces gold equivalent grading 3.52 grams per tonne gold and 0.50 per cent copper (4.258 g/t AuEq) contained within 590,000 metric tonnes (using a net smelter return (NSR) cut-off of $30).
• Increase in average grade, and resource constrained to reasonable prospects of eventual economic extraction pit shell.
• Conservative metal recoveries assumption of 60 per cent Au and 77 per cent Cu based on limited 2008 metallurgical work.
• Global in situ strip ratio of 5.5:1.0 based on a conservative 50-degree pit slope angle.
• Geological model indicates potential targets on strike and at depth of current 2023 MRE.
• Merry Widow 2023 MRE represents only 200-metre strike length of an overall greater-than-two-kilometre trend.

The Merry Widow open-pit area is one of 15 exploration target zones at Empire identified from historical drilling by previous operators and more recent exploration conducted by Coast Copper. Empire also includes a target zone at the historical Benson Lake mine/Old Sport Horizon with copper and gold potential covering approximately three square kilometres based on historical exploration and mining completed by Cominco Resources. To note, the 2023 MRE does not include the historical Benson Lake mine reserves.

The updated resource is presented herein. Sue Bird, MSc, PEng, of Moose Mountain Technical Services (MMTS) was contracted to calculate the 2023 MRE published within this news release. An updated technical report will be filed on Coast Copper's website and with SEDAR within 45 calendar days of this disclosure.

Adam Travis, Coast Copper's chief executive officer, commented: "The Empire mine property covers 23 mineral occurrences, including three past-producing open-pit and two past-producing underground mines. The 2023 MRE at the Merry Widow open pit covers an area approximately 200 m by 100 m which is a small portion of the known exploration footprint on the property. Empire includes 15 identified exploration target zones of which the Merry Widow open pit is the first that Coast Copper has tested. Therefore, this 2023 MRE should be considered a proof of concept that takes the historical information, combines it with our recent drilling and geophysics programs, and delivers a[n] NI 43-101 mineral resource estimate that shows substantial improvements over the previously published historical estimate in 2008. Furthermore, the 2023 MRE covers just 25 m of the known 200 m strike length between the Merry Widow open pit and the Raven pit located to the north. We expect to publish an exploration target range in due course as we systematically look to unlock the known potential at Empire."

Interpretation

The work completed on the geological model provides proof of concept that zones of significant mineralization occur not only along the intrusive dike margins, but also along the structural intersections of thrust and high-angle faults. As previously announced by Coast Copper (see news release Jan. 18, 2023), this reinforces the potential for multiple high-grade, near-surface targets along the two km upper Merry Widow trend.

Updating the previous geological model and constraining the resource to reasonable prospects of eventual economic extraction pit shell resulted in an increase of average gold and copper grades as compared with the 2008 resource. The gold grade increased by 73 per cent from 2.03 g/t to 3.52 g/t and the copper grade increased by 50 per cent from 0.34 per cent to 0.51 per cent (excluding any potential credits for cobalt, silver and magnetite). Future work will include further investigation into these potentially significant accessory metal constituents.

Due to limited metallurgical data from test work conducted in 2008 from drill core samples, the 2023 MRE applied conservative recoveries of 60 per cent Au and 77 per cent Cu. In 2010, further metallurgical work by Grande Portage reported recoveries of 95 per cent Au and 88 per cent Cu from a small bulk sample. Given the discrepancy between recovery values, the company plans to complete a proper metallurgical test program on the representative material types to improve metal recoveries in the near future.

The 2023 MRE examined possible parameters affecting economics such as pit shapes and pit slopes. A very conservative pit slope of 50 degrees was used even though the previous Merry Widow pit, which ceased production in 1968, currently stands up well with a significantly steeper overall pit slope. To maximize the pit slope angles and reduce strip ratio, Coast Copper will look at completing a geotechnical assessment of the open pit and lab testing for optimal pit design.

Due to a lack of modern quality assurance/quality control standards and incomplete sampling from 1989 to 1990 drill assay data, some data from the field programs were not able to be used in the 2023 MRE. Although some data were not used in the calculation of the 2023 MRE, the assay data and geological observations will be used to target historically mineralized areas, especially those that are noted to occur outside the 2023 MRE. The 500 m long Kingfisher adit was established by Empire Mines in 1960, approximately 107 m below the bottom of the Merry Widow pit, to extract further magnetite resource by block caving methods below the Merry Widow pit. Rock chip sampling, geological observations and observed mineralization within this adit during the 2022 field program have returned values up to 3.4 g/t Au and 2.6 per cent Cu (see news release Aug. 15, 2022), indicating potential resource expansion at depth.

Coast Copper expects to outline additional mineral resource potential for the Merry Widow open-pit area in a coming press release. Exploration efforts will focus on expanding the Merry Widow mineralized trend along strike to the north-northeast toward Raven pit/Bluff as well as to the south toward Marten, where it has completed initial drill testing that has highlighted the potential for the system to occur in both directions. Further exploration efforts will be followed at depth below the Merry Widow open pit where copper and gold mineralized skarn as well as magnetite skarn were sampled along the Kingfisher underground which is up to 40 m below the 2023 MRE. The company expects to complete this in due course.

Mirva Properties Ltd. has retained a 2-per-cent NSR royalty on the Empire mine property, of which 1 per cent may be purchased for $1-million at any time up to 120 days after commencement of commercial production. The Empire option agreement has been structured such that this NSR royalty plus all other NSR royalties which may currently exist and be payable on the Empire mine property will not exceed in aggregate 2.5 per cent before buydowns.

Key assumptions and methods used for mineral resource estimate

Updates from the previous model by Giroux in 2008 included the addition of drill holes from Coast Copper's 2021 drill program, incorporating results from 1989 underground chip sampling for interpretations, updated interpretations of the mineralized resource envelope, drill hole data validations, updated grade capping and the use of current economic factors to develop a reasonable prospects of eventual economic extraction pit.

Mineralization envelope

Implicit modelling tools were used to develop a mineralization envelope which targets a minimum $20 NSR value cut-off in a smooth and continuous shape. The shape was then clipped away from mined out areas. The clipping distance is 10 m in plan and 20 m vertical from the provided underground stope survey.

These parameters assume a copper concentrate with gold credits as per the preliminary metallurgical testing done in 2008 and 2010 and overseen by Gary Hawthorn, PEng.

Data verification

A review of the drill hole data was undertaken and after statistical validation it was determined that the 1989 data were biased high for gold, low for silver and acceptable for interpolation of copper. Data from 1989 drill holes were considered in the development of the mineralization envelope but were not used in interpolations due to lack of certificates and QA/QC as well as the inability to have confidence in the 1989 grades. The model was run using the 1989 data only for copper.

Variography and interpolations

The block model utilized a 10 m by 10 m by five m selective mining unit with interpolation of copper and gold done using multiple passes of inverse distance cubed with the variography as the basis of the interpolation search parameters. Variography found that within the mineralization the strongest correlation of assay values is trending at azimuth 160 dipping 40 degrees with a range of approximately 40 m.

Grade capping

Cumulative probability plots were used to establish gold and copper capping and outlier values. The attached table summarizes the capping done on the assays prior to compositing and the outlier restrictions done to the composites during interpolation. For composite grades above the outlier value provided, and at distances greater than five m from the data, the value is essentially capped.

Specific gravity and resource pit limits

Specific gravity (SG) is variable within the mineralization envelope, probably because of the presence of both lower SG dikes which are too thin to model and areas of higher SG sulphides and magnetite. SG was interpolated using two passes of inverse distance squared interpolation using the same search parameters as pass 3 and 4 of the gold/copper interpolation. SG values were capped at 4.6 prior to interpolation and any blocks not reached by the interpolation were assigned SG of 3.35 which is the median of the capped values.

Lerch Grossman pit optimization tools have been used to select a pit shape for limiting the resource. The LG pit targets NSR calculated in each block using copper and gold interpolation results.

Qualified persons

The technical information contained in this news release has been prepared, reviewed and approved by Wade Barnes, PGeo (British Columbia), Coast Copper's geological consultant and a qualified person within the context of Canadian Securities Administrators' National Instrument 43-101 -- Standards of Disclosure for Mineral Projects.

The 2023 MRE has been provided by Ms. Bird, MSc, PEng, geological and mining engineer (NI 43-101 qualified person) of MMTS.

About Coast Copper Corp.

Coast Copper's exploration focus is the optioned Empire mine property, located on northern Vancouver Island, B.C., which covers three historical open-pit mines and two past-producing underground mines that yielded iron, copper, gold and silver. Coast Copper's other properties include its 100-per-cent-owned Knob Hill NW property located on northern Vancouver Island, its Home Brew and Shovelnose South properties in central B.C., and its Scottie West property located in the Golden Triangle of Northern B.C. Coast Copper's management team continues to review precious and base metals opportunities in western North America.

We seek Safe Harbor.