Mr. Darren Pylot reports

CAPSTONE MINING 2018 FIRST QUARTER PRODUCTION RESULTS

Capstone Mining Corp. has released production results for the three months ended March 31, 2018. Combined production totalled 19,200 tonnes of copper in the first quarter, with additional byproducts of zinc, molybdenum, lead, silver and gold.

      FIRST QUARTER 2018 COPPER PRODUCTION 
                  (tonnes)
Pinto Valley                             11,400
Cozamin                                   4,300
Minto                                     3,500
Total copper production (1)              19,200

(1) Total production includes copper 
in concentrate and cathode production.
  

"Cozamin outperformed in the first quarter, with production at Pinto Valley slightly lower than expectations and Minto impacted by lower grades," said Darren Pylot, president and chief executive officer of Capstone. "Consolidated production is expected to ramp up throughout the remaining quarters, aligned with our 2018 guidance.

"In the first quarter, we also announced an agreement to sell our Minto mine to Pembridge Resources PLC," added Mr. Pylot. "The transaction is progressing as planned and is expected to complete in the second quarter, with the proceeds earmarked to pay down our credit facility."

Operational highlights:

• At Pinto Valley, production was lower than planned with throughput and recoveries at the low end of expectations. Grade was in line with the mine plan for the quarter, with higher head grade and production expected over the remainder of the year.
• At Cozamin, production for the quarter was better than expected on higher grade.
• At Minto, production was lower than planned with mining delays in the underground operations and lower-than-expected grades coming from the area 2 stage 4 pushback, resulting in lower-grade mill feed during the quarter.

                                 FIRST QUARTER 2018 OPERATING DETAILS   
                                                                              
                                          Pinto Valley       Cozamin         Minto         Total
Contained production (1)
Copper (tonnes)                                 11,421         4,285         3,530        19,236
Zinc (tonnes)                                        -           795             -           795
Molybdenum (Mo tonnes)                              29             -             -            29
Lead (tonnes)                                        -            21             -            21
Silver (ounces) (2)                             70,435       250,175        35,404       356,014
Gold (ounces) (2) (3)                                -             -         2,600         2,600
Payable copper production (1) (tonnes)
(in concentrate and cathode)                    11,037         4,115         3,415        18,567
Mine
Ore (tonnes) -- open pit                     5,065,704             -       474,549     5,540,253
Waste (tonnes)                               6,789,137             -     1,312,512     8,101,649
Ore (tonnes) -- underground                          -       214,942        90,921       305,863
Mill
Tonnes processed                             4,834,434       212,912       366,578     5,413,924
Tonnes processed per day                        53,716         2,366         4,073        60,155
Copper grade (%) (4)                              0.27          2.09          1.16          0.40
Zinc grade (%)                                       -          0.62             -          0.62
Molybdenum grade (%)                             0.006             -             -         0.006
Lead grade (%)                                       -          0.08             -          0.08
Silver grade (g/t)                                   *            45             4            19
Gold grade (g/t)                                     *             -          0.35          0.35
Recoveries (%)
Copper                                        83.1 (4)          96.3          82.9          85.8
Zinc                                                 -          59.8             -          59.8
Lead                                                 -          12.4             -          12.4
Silver                                               *          81.4          75.0          80.5
Gold                                                 *             -          55.2          55.2
Concentrates
Copper concentrate (dmt)                        43,847        15,810         8,990        68,647
Copper (%)                                        25.0          27.1          39.3          27.4
Silver (g/t)                                         *           487           123           355
Gold (g/t)                                           *             -           7.9           7.9
Zinc concentrate (dmt)                               -         1,667             -         1,667
Zinc (%)                                             -          47.7             -          47.7
Molybdenum concentrate (dmt)                        58             -             -            58
Lead concentrate (dmt)                               -            38             -            38
Lead (%)                                             -          54.4             -          54.4
Silver (g/t)                                         -         2,109             -         2,109
Payable copper shipped (tonnes)                 12,372         3,831         3,924        20,127

(1) Adjustments based on final settlements will be made in future periods. 
(2) Silver and gold at Pinto Valley and gold at Minto are not assayed on site, resulting in 
a significant lag time in receiving these data. As such, these figures are estimates and for 
Minto includes gold contained in copper concentrate, but excludes gold contained in gold 
concentrate produced. 
(3) Pinto Valley gold production reaches payable levels from time to time. Any payable gold 
production will be reported in the period revenue is received. 
(4) Grade and recoveries were estimated based on concentrate production and may be impacted 
by settlements from prior production periods.  
* Silver and gold have not been estimated in the Pinto Valley resource model. 
Only recovered silver and payable gold are reported for this mine.

Operating outlook

Capstone's 2018 copper production guidance for Pinto Valley and Cozamin remains unchanged. Capstone has entered into a definitive agreement for the sale of the Minto mine, with the transaction expected to close in the second quarter of 2018.

Financial results timing

Capstone will report first quarter 2018 financial results on Tuesday, April 24, 2018, after market close, followed by a conference call and webcast for investors and analysts on Wednesday, April 25, 2018, at 11:30 a.m. Eastern Time (8:30 a.m. Pacific Time).

Conference call and webcast details:

Date:  Wednesday, April 25, 2018

Time:  11:30 a.m. Eastern Time (8:30 a.m. Pacific Time)

Dial-in numbers:

North America:  1-888-390-0546

International:  416-764-8688

Replay:

North America:  1-888-390-0541

International:  416-764-8677

Replay pass code:  285507 followed by the number sign

The conference call replay will be available until Wednesday, May 2, 2018. The conference call audio and transcript will be available on Capstone's website within 48 hours of the call.

About Capstone Mining Corp.

Capstone is a Canadian base metals mining company, focused on copper. It is committed to the responsible development of its assets and the environments in which it operates. Its three producing mines are the Pinto Valley copper mine located in Arizona in the United States, the Cozamin polymetallic mine in Zacatecas state, Mexico, and the Minto copper mine in Yukon, Canada. In addition, Capstone has the large-scale, 70-per-cent-owned copper-iron Santo Domingo development project in Region III, Chile, in partnership with Korea Resources Corp., as well as exploration properties in Chile.

We seek Safe Harbor.