Capstone Mining Announces Exploration Drill Results and Increases Land Position at Cozamin Mine

VANCOUVER, British Columbia, September 12, 2017 /PRNewswire/ --

Capstone Mining Corp. ('Capstone' or the 'Company') (TSX: CS) today announced drill results of step-out drilling at its Cozamin mine in Mexico. A half kilometre step-out drill hole intercepted 2.2% copper over 14.4 metres ('m') estimated true width ('ETW'); including 4.4% copper over 6.3m ETW in hole S285.

"Based on confidence gained in several consecutive, annual underground drilling campaigns on the Mala Noche Footwall Zone ('MNFWZ'), we recently added two surface rigs to step up the pace of exploration and facilitate better long-range planning. Our furthest step-out hole to date intercepted strong copper mineralization 580 metres along strike to the southeast from the limits of the current MNFWZ Indicated Mineral Resource," said Brad Mercer, Capstone's Senior Vice President, Exploration. "We encountered copper grades in excess of 4% immediately adjacent to Endeavour Silver Corp. ('Endeavour') claims over larger than average widths than typical of the MNFWZ (see table below). As a result, we have entered into an agreement with Endeavour which allows us to follow the footwall structure beyond the boundary of our concession."

The agreement Capstone has entered into (the 'Agreement') with Endeavour Silver Corp. ('Endeavour') allows for the two companies to exchange access to certain of each other's mining concessions that abut at the southern boundary of Capstone's Cozamin mine property. The agreement provides Capstone with exploration and exploitation rights on the Endeavour concessions below 2,000 metres above sea level ('masl'), a depth where copper rich mineralization has historically been found and mined by Capstone, and provides Endeavor with exploration and exploitation rights on the Capstone concessions above 2,000 masl, where more precious metal dominant mineralization has historically been mined, in the historic Zacatecas silver district.

The Agreement provides for both parties to share various information on the concessions covered by the Agreement and to jointly have access to explore for and exploit mineralization appropriate to each company's core business; being base metals for Capstone and precious metals for Endeavour. In certain instances it also provides for a net smelter returns royalty for the entity electing not to produce. Additionally, and under certain well-defined instances, it provides flexibility around the 2,000 masl division.

Capstone has completed four surface holes with an additional two holes in progress near the claim boundary, and as a result of the recent success has approved a further $1.3 million to Cozamin's 2017 capitalized exploration guidance to continue wide-spaced testing of the MNFWZ structure on both sides of the Capstone/Endeavour boundary.

A summary of assay results of the step-out hole intercepts underpinning Capstone's decision to enter into this agreement are summarized in the table below. For drill hole location and context please view the long-section of the MNFWZ at: http://capstonemining.com/files/images/maps/MNFWZ.jpg

Section Drill hole From To Width True Cu Zn Pb Ag Au ID ID (m) (m) (m) Width*(m) (%) (%) (%) (g/t) (g/t) CG-17-S284 773.0 792.9 19.9 15.0 1.01 0.37 0.12 19.1 0.006 including 777.0 791.7 14.7 11.0 1.24 0.48 0.15 22.8 0.005 including 777.0 782.8 5.8 4.4 2.42 0.43 0.01 33.7 0.008 #1 including 777.0 779.4 2.4 1.8 5.37 0.33 0.01 70.9 0.012 CG-17-S285 733.1 752.5 19.4 4.4 2.19 0.76 0.35 52.4 0.015 including 733.1 744.7 11.6 8.7 3.41 1.13 0.55 79.9 0.018 including 735.4 743.9 8.5 6.3 4.43 1.36 0.73 104.3 0.022 #2 including 739.3 742.7 3.4 2.5 7.65 1.08 0.90 182.1 0.023 #3 CG-17-S287 - - - - Assays Pending CG-17-S289 731.2 736.8 5.6 4.6 3.03 0.55 0.01 53.8 0.022 #4 including 731.2 733.9 2.7 2.3 5.05 0.98 0.01 87.0 0.022 #5 CG-17-S291 - - - - In Progress #6 CG-17-S292 - - - - In Progress *estimated true width of vein intercept for inclined drill holes

All samples were submitted for preparation by ALS at its facilities in Zacatecas, Mexico, followed by analysis at the ALS Laboratory in North Vancouver, Canada. The entire sample is crushed to a minimum of 70% passing -10 mesh. A 250g subsample of the crushed material is then pulverized to 85% passing -200 mesh. Copper, zinc, lead and silver are determined by ICP analysis after 4 acid digestion of a 0.4g subsample of pulverized material. Gold is determined by fire assay of a 30g sub-sample with AA finish. QAQC samples in each batch of 20 samples include a blank, a certified reference material and a duplicate (one of a field, coarse reject or pulp reject).

AboutCapstoneMiningCorp.

Capstone Mining Corp. is a Canadian base metals mining company, focused on copper. We are committed to the responsible development of our assets and the environments in which we operate. Our three producing mines are the Pinto Valley copper mine located in Arizona, US, the Cozamin polymetallic mine in Zacatecas State, Mexico and the Minto copper mine in Yukon, Canada. In addition, Capstone has two development projects; the large scale 70% owned copper-iron Santo Domingo project in Region III, Chile, in partnership with Korea Resources Corporation, and the 100% owned Kutcho copper-zinc project in British Columbia, Canada, as well as exploration properties in Chile and US. Capstone's strategy is to focus on the optimization of operations and assets in politically stable, mining-friendly regions, centred in the Americas. Our headquarters are in Vancouver, Canada and we are listed on the Toronto Stock Exchange (TSX). Further information is available at http://www.capstonemining.com.

CautionaryNoteRegardingForward-LookingInformation

This document may contain "forward-looking information" within the meaning of Canadian securities legislation and "forward-looking statements" within the meaning of the United States Private Securities Litigation Reform Act of 1995 (collectively, "forward-looking statements"). These forward-looking statements are made as of the date of this document and Capstone does not intend, and does not assume any obligation, to update these forward-looking statements, except as required under applicable securities legislation.

Forward-looking statements relate to future events or future performance and reflect our expectations or beliefs regarding future events. Forward-looking statements include, but are not limited to, statements with respect to the continuing success of mineral exploration, Capstone's ability to fund future exploration activities, the realization of mineral reserve estimates, the timing and amount of estimated future production and the success of mining operations. In certain cases, forward-looking statements can be identified by the use of words such as "plans", "expects", "budget", "scheduled", "estimates", "forecasts", "intends", "anticipates", "believes" or variations of such words and phrases, or statements that certain actions, events or results "may", "could", "would", "might" or "will be taken", "occur" or "be achieved" or the negative of these terms or comparable terminology. In this document certain forward-looking statements are identified by words including "subject", "expected" and "intend". By their very nature, forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Such factors include, amongst others, risks related to inherent hazards associated with mining projects, future prices of copper and other metals, changes in general economic conditions, and other risks of the mining industry as well as those factors detailed from time to time in the Company's interim and annual financial statements and management's discussion and analysis of those statements, all of which are filed and available for review under the Company's profile on SEDAR at http://www.sedar.com. Although the Company has attempted to identify important factors that could cause our actual results, performance or achievements to differ materially from those described in our forward-looking statements, there may be other factors that cause our results, performance or achievements not to be as anticipated, estimated or intended. There can be no assurance that our forward-looking statements will prove to be accurate, as our actual results, performance or achievements could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on our forward-looking statements.

NationalInstrument43-101Compliance
Unless otherwise indicated, Capstone has prepared the technical information in this news release ("Technical Information") based on information contained in the technical reports, news releases and MD&A's (collectively the "Disclosure Documents") available under Capstone Mining Corp.'s company profile on SEDAR at http://www.sedar.com. Each Disclosure Document was prepared by, or under the supervision of, a qualified person (a "Qualified Person") as defined in National Instrument 43-101 StandardsofDisclosureforMineralProjects of the Canadian Securities Administrators ("NI 43-101"). Readers are encouraged to review the full text of the Disclosure Documents which qualifies the Technical Information. Readers are advised that mineral resources that are not mineral reserves do not have demonstrated economic viability. The Disclosure Documents are each intended to be read as a whole, and sections should not be read or relied upon out of context. The Technical Information is subject to the assumptions and qualifications contained in the Disclosure Documents.

The technical information in this news release ("Technical Information") was prepared by, or under the supervision of, a qualified person (a "Qualified Person") as defined in National Instrument 43-101 StandardsofDisclosureforMineralProjects of the Canadian Securities Administrators ("NI 43-101"). The disclosure of the Technical Information contained in this news release has been reviewed and approved by Gregg Bush, P. Eng., Senior Vice President and Chief Operating Officer. Technical Information related to mineral exploration activities has been reviewed and approved by Brad Mercer, P. Geol., Senior Vice President, Exploration. Both are Qualified Persons under NI 43-101.

Media Contact:
Cindy Burnett
VP, Investor Relations and Communications
+1-604-637-8157
cburnett@capstonemining.com