Endeavour Makes Significant High Grade Discoveries at Houndé

ENDEAVOUR MAKES SIGNIFICANT HIGH GRADE DISCOVERIES AT HOUNDÉ
Kari Pump target significantly extended · 2 new discoveries made in the Kari area · Further drilling underway

HOUNDé EXPLORATION HIGHLIGHTS:

• Following last year's Kari Pump discovery, more than 1,000 holes comprising 76,000m have already been drilled in the wider Kari area, located only 7km away from the Houndé processing plant
• The Kari mineralized zone has been significantly extended to a large area now measuring 4km long and 3km wide, with approximately 25% of the gold in soil anomaly still remaining to be drilled
• Kari area is now comprised of three large high-grade discoveries:
  • Drilling at the previously discovered Kari Pump target confirmed its high-grade nature and significantly expanded its mineralization which now extends 1.3km along strike and across a width of 160 to 200m, while remaining open to the north and northwest
  • Kari Center discovery made which extends 1.2km along strike and across a width of over 200m, with mineralization open at depth
  • Kari West high-grade discovery made which extends at least 1.0km along strike and across a width of 500m, with mineralization open at depth and towards Kari Pump
• A further 65,000m drilling campaign is underway to delineate and extend the three discoveries made, with in-fill drilling planned on the Kari Pump target to obtain maiden resource by year-end

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Abidjan, May 24, 2018 - Endeavour Mining (TSX:EDV)(OTCQX:EDVMF) is pleased to announce that the on-going exploration program at its Houndé mine in Burkina Faso has successfully extended the Kari Pump high grade mineralization and has discovered two new large mineralized zones named Kari Centre and Kari West.

Following the Kari Pump discovery, announced on November 13^th 2017, exploration efforts were prioritized on the wider Kari area which hosts a large gold-in-soil geochemical anomaly covering a 6km-long by 2.5km-wide area. Kari is located only 7km west of the processing plant and in proximity to an existing haul road that will be used to transport ore from Bouéré.

More than 1,000 holes comprising 76,000 meters have already been drilled in the Kari area since late December, extending the mineralized zone to a very large area now measuring 4km long and 3km wide, with approximately 25% of the gold-in-soil anomaly remaining to be drilled.

Patrick Bouisset, Executive President Exploration and Growth stated: "Following the initial discovery made last year, we have undertaken an extensive drilling campaign on the wider Kari target due to its potential size and higher-grade nature. With more than half of the planned 141,000-meter drilling program complete, we are extremely pleased with the results as they validate its potential and we are eager to delineate a first maiden resource on the Kari Pump area by year-end."

Sebastien de Montessus, President & CEO, added: "With Houndé ramped-up and the plant performing above nameplate capacity, we are now eager to pursue additional upside from exploration. These new discoveries provide confidence in achieving our strategic objective of maintaining a steady production profile at an attractive All-in Sustaining Cost over at least 10-years.

ABOUT THE ONGOING HOUNDÉ EXPLORATION PROGRAM

Following the construction decision to develop the Houndé mine, exploration resumed in early 2017 with an initial reconnaissance drilling campaign prioritizing various targets identified during the 2016 exploration strategic review. In 2017, the campaign validated Hounde's significant exploration potential as high-grade mineralization was intercepted at the Kari, Sia/Sianikoui, and Bouéré extension targets. Given its potential size, the Kari target was identified as a top priority, and a circa $9 million exploration program totaling over 141,000 meters was launched in 2018 to follow-up on the Kari Pump discovery and to explore the undrilled portion of the large Kari gold-in-soil geochemical anomaly which covers a 6km-long by 2.5km-wide area.

The exploration campaign began in late December 2017 and more than 1,000 holes totaling 76,000 meters have been drilled to date on the various Kari targets, comprised of approximately 900 Air Core ("AC") reconnaissance holes totaling 63,500 meters and 120 Reverse Circulation ("RC") holes totaling more than 14,900 meters. The campaign has been very successful with more than 65% of the 120 RC holes encountering at least one interval of mineralisation of 0.5 g/t Au with a minimum width of more than 2 meters. Drilling successfully extended the Kari Pump high grade mineralization and discovered two new large mineralized zones named Kari Centre and Kari West, as shown in Figure 1 below. To date, these targets were investigated by mainly shallow AC drilling with the majority of the reported mineralization located within the saprolite zone, at a vertical depth not exceeding 60 to 80 meters.

The previous 2017 exploration campaign on the Kari Pump target comprised of 337 AC/RC holes totaling 30,460 meters, 23 RC holes totaling of 3,400 meters and few Diamond Drilling ("DD") holes.

Figure 1: Simplified Houndé Exploration Targets Map

As shown in Figure 2 below, to date the mineralized Kari zone now covers a very large area extending over more than 4km in length and 3km in width. The two new discoveries (Kari Center and Kari West) are located in close proximity to Kari Pump and more drilling is still required to determine a possible geological link between the discoveries.

Figure 2: Kari Area Mineralized Envelops (500 ppb Leapfrog Envelops)

KARI PUMP DISCOVERY

Additional recent drilling carried out on the Kari Pump target has confirmed both the previous geological interpretation and its high-grade nature, while significantly extending the mineralization to the northeast and east, where significant high-grade intersections have been encountered. The target was successfully drilled along a strike length of over 1.3km, and across a width of more than 100 to 200 meters.

As shown in Figure 3 of the Appendix, the Kari Pump mineralization remains open to the north, northeast and to the northwest. An infill drill program is ongoing with the aim of delivering a maiden resource estimate in Q4-2018.

Selected intersects include (true width uncapped):

• RCA-18-016 : 8.9m @ 3.0 g/t Au, (including 0.99m @ 8.5 g/t)
• RCA-18-028 : 10.9m @ 17.1 g/t Au (including : 1.9m @ 34.6 g/t Au, 1.9m @ 30.8 g/t Au and 0.9m @ 22.7 g/t Au)
• RC-18-030 : 12.5m @ 3.4 g/t Au (including 1.9m @ 7.8 g/t Au)
• RC-18-009 : 5.8m @ 8.0 g/t Au (including 1.9m @ 17.5 g/t Au)
• RC-18-006 : 8.7m @ 5.1 g/t Au (including 2.9m @ 11.1 g/t Au) and 3.86m @ 1.3 g/t Au
• RC-18-010 : 2.9 m @ 15.1 g/t Au

Geologically, Kari Pump is underlain by andesite flows with minor volcano-sediment and sediments that are locally intruded by few diorite sills. Gold mineralization occurs within a sheared reverse fault (D2) that appears to be folded and dipping from 0-40 degrees to the west-northwest and northwest. Observed clear alteration consists of pervasive creamy sericite, intermittent rhodochrosite, chlorite seams and pyritized quartz/carbonate veining. The laterite and saprolite are relatively thick at Kari Pump with an average thickness which ranging from 50 to 85 meters.

KARI CENTER DISCOVERY
Mineralization was first intercepted at Kari Center during the initial 2017 reconnaissance drilling campaign. Further 2018 drilling then confirmed the high grade intersections and significantly extended the mineralization. Gold mineralization dips are interpreted as being 40-60 degrees dipping to the northwest with two parallel mineralized zones (40 meters apart) that extend northeast along a strike length of at least 800 meters and across a width of over 200 meters.

Selected intersects include (Apparent width uncapped):

• RCB-18-006 : 1.9m @ 3.1 g/t Au And 3.8 m @ 3.5 g/t Au (Incl. 0.9m @ 8.9 g/t Au) And 4.7m @ 1.4 g/t Au And 5.6m @ 3.0 g/t (Incl. 1.9m @ 6.2 g/t Au)
• RCB-18-029 : 2.8m @ 13.9 g/t Au (Incl. 0.9m @ 39.6 g/t Au)
• RCB-18-027-279 : 5.6m @ 1.5 g/t Au and 1.9m @ 1.2 g/t Au, and 1.9m @ 4.6 g/t Au (Incl. 0.9m @ 7.7 g/t)

Geologically, Kari Center is underlain by andesite flows and sediments. The structural context however remains complex and will require additional DD holes to better understand the structural behavior and relationship between the mineralized intersects. This drill program, which will be completed in H2-2018, should confirm its type of mineralization, dip and strike.

KARI WEST DISCOVERY
Kari West was discovered during the 2018 AC drilling campaign focusing on the remaining undrilled wider Kari gold-in-soil geochemical anomaly. To date, reconnaissance drilling has successfully defined a mineralized area of at least 1km in strike length at a width of 500 meters. The geological and structural context of Kari West is yet to be well understood and is currently being tested with further diamond drill holes. Preliminary results however suggest the presence of two parallel mineralized zones located between 200 and 300 meters apart that appear to strike east-northeast and dip between 0 and 60 degrees to the north.

Selected intersects include (Apparent width uncapped):

• ACB-18-0003 : 4.3m @ 1.5 g/t Au and 6.0m @ 3.6 g/t Au (Incl. 1.7m @ 9.1 g/t), And1.7m @ 5.1 g/t Au, And 1.7m @ 1.5 g/t Au)
• ACA-18--0264 : 5.2m @ 7.3 g/t Au (Incl. 1.7m @ 10.3 g/t)
• ACA-18-0147 : 5.2m @ 5.6 g/t Au (Incl. 0.9m @ 15.8 g/t); and 1.7m @ 7.3 g/t Au
• ACA-18-0368 : 3.5m @ 3.5 g/t Au
• ACA-18-0267 : 6.0m @ 2.7 g/t Au And 1.7m @ 2.3 g/t Au and 6.0 m @ 4.4 g/t Au (Incl. 1.7m @ 13.4 g/t Au)

The ongoing RC drill program is currently based on a grid of 200 by 50 meters which will be tightened in upcoming drill campaigns. Laterite and saprolite thicknesses vary between 25 and 75 meters.

HOUNDÉ NEXT STEPS

At a minimum, 65,000 meters of additional drilling are expected to be completed before year-end.

An AC and RC drilling program is already underway to further delineate and extend the three discoveries made and test the remaining un-drilled Kari area.

In addition to the AC and RC drilling program, a dedicated DD drilling campaign is also ongoing at Kari Pump, Kari West and Kari Center in order to increase confidence in the geological interpretation and to provide technical support for the resources classification requirements.

An in-fill drilling program is planned on the Kari Pump target to obtain a maiden Indicated resource estimate by year-end.

QUALIFIED PERSONS

The scientific and technical content of this news release has been reviewed, verified and compiled by Gérard de Hert, EurGeol, Senior VP Exploration for Endeavour Mining. Gérard de Hert has more than 20 years of mineral exploration and mining experience, and is a "Qualified Person" as defined by National Instrument 43-101 - Standards of Disclosure for Mineral Projects ("NI 43-101").

ASSAYS AND QUALITY ASSURANCE/QUALITY CONTROL / DRILLING AND ASSAY PROCEDURES

The Reverse Circulation drill program samples were collected on a 1-meter interval using dual tube, a percussion hammer and drop centre bit. The material passes through a cyclone which is thoroughly cleaned after every sample by flushing the hole. Samples were split at the drill site using a 3-tier riffle splitter with both bulk and laboratory sample weights and moisture recorded. 3-5 Kg laboratory samples were collected and sent to ALS-CHEMEX (ALS) in Ouagadougou (Burkina Faso). Representative samples for each interval were collected with a spear, sieved into chip trays and retained for reference. The sampling and assaying at Houndé is monitored through the implementation of a quality assurance - quality control (QA-QC) program. This QA-QC program was audited by International mining consultant and consequently designed to follow industry best practices.

The laboratory samples are collected by ALS on site and transported by road to ALS in Ouagadougou, Burkina Faso. Each laboratory sample is secured in poly-woven bags ensuring that there is a clear record of the chain of custody. On arrival samples are weighed and crushed to 6mm (70% passing), pulverize entire sample to 75 micrometers (85% passing). Samples are analyzed for gold using standard fire assay technique with a 50-gram charge and an Atomic Absorption (AA) finish and gravimetric finish when grade exceeds 10 ppm. Blanks and certified reference material (CRM's) are inserted by Endeavour geologists in the sample sequence for quality control and to ensure there are a suite of QC samples in each fire assay batch.

Click here to view the 2018 completed drill results on the Kari target.

CONTACT INFORMATION

ABOUT ENDEAVOUR MINING CORPORATION

Endeavour Mining is a TSX listed intermediate African gold producer with a solid track record of operational excellence, project development and exploration in the highly prospective Birimian greenstone belt in West Africa. Endeavour is focused on offering both near-term and long-term growth opportunities with its project pipeline and its exploration strategy, while generating immediate cash flow from its operations.

Endeavour operates 5 mines across Côte d'Ivoire (Agbaou and Ity), Burkina Faso (Houndé, Karma), and Mali (Tabakoto) which are expected to produce 670-720koz in 2018 at an AISC of $840-890/oz. Endeavour's high-quality development projects (recently commissioned Houndé, Ity CIL and Kalana) have the combined potential to deliver an additional 600koz per year at an AISC well below $700/oz between 2018 and 2020. In addition, its exploration program aims to discover 10-15Moz of gold between 2017 and 2021 which represents more than twice the reserve depletion during the period.

For more information, please visit www.endeavourmining.com.

Corporate Office: 5 Young St, Kensington, London W8 5EH, UK

This news release contains "forward-looking statements" including but not limited to, statements with respect to Endeavour's plans and operating performance, the estimation of mineral reserves and resources, the timing and amount of estimated future production, costs of future production, future capital expenditures, and the success of exploration activities. Generally, these forward-looking statements can be identified by the use of forward-looking terminology such as "expects", "expected", "budgeted", "forecasts", and "anticipates". Forward-looking statements, while based on management's best estimates and assumptions, are subject to risks and uncertainties that may cause actual results to be materially different from those expressed or implied by such forward-looking statements, including but not limited to: risks related to the successful integration of acquisitions; risks related to international operations; risks related to general economic conditions and credit availability, actual results of current exploration activities, unanticipated reclamation expenses; changes in project parameters as plans continue to be refined; fluctuations in prices of metals including gold; fluctuations in foreign currency exchange rates, increases in market prices of mining consumables, possible variations in ore reserves, grade or recovery rates; failure of plant, equipment or processes to operate as anticipated; accidents, labour disputes, title disputes, claims and limitations on insurance coverage and other risks of the mining industry; delays in the completion of development or construction activities, changes in national and local government regulation of mining operations, tax rules and regulations, and political and economic developments in countries in which Endeavour operates. Although Endeavour has attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking statements, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that such statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements. Please refer to Endeavour's most recent Annual Information Form filed under its profile at www.sedar.com for further information respecting the risks affecting Endeavour and its business. AISC, all-in sustaining costs at the mine level, cash costs, operating EBITDA, all-in sustaining margin, free cash flow, net free cash flow, free cash flow per share, net debt, and adjusted earnings are non-GAAP financial performance measures with no standard meaning under IFRS, further discussed in the section Non-GAAP Measures in the most recently filed Management Discussion and Analysis.

APPENDIX 1

Figure 3: Kari Pump Area with isosurfaces (Leapfrog) and typical thickness/grade per area
(0.5ppm modelisation + Composites >2m and >1ppm (1m dilution) Looking North, 30 degree plunge)
Where insufficient drill hole spacing (200m x 50m) and the geological model still preliminary and to be cautious, drilling results shown in the figure are therefore only reported in true width where the geological model is well understood and apparent width when the geological model is still approximate.

Figure 4: Kari Pump Long-Section 1

Figure 5: Kari Pump Cross-Section 2

Attachments

• Kari Area Mineralized Envelops (500 ppb Leapfrog Envelops).jpg
• Kari target drill results.xlsx
• Simplified Houndé Exploration Targets Map.png
• Kari Pump Long-Section 1.png
• Kari Pump Area with isosurfaces (Leapfrog).jpg
• Kari Pump Cross-Section 2.png
• View News Release in PDF Format.pdf