IDM Mining's Step-Out Drilling at SF Zone Intersects 8.00 meters Averaging 12.28 g/t Au and 27.07 g/t Ag, 275 meters Along Strike from Current Reserves

VANCOUVER, BRITISH COLUMBIA--(Marketwired - Aug. 9, 2017) - IDM Mining Ltd. (TSX VENTURE:IDM)(OTCQB:IDMMF) ("IDM" or the "Company") is pleased to announce assays for an additional three underground core holes from the SF Zone at the Red Mountain Gold Project ("Red Mountain" or the "Project"), located 15 km east of Stewart, B.C. Previous drilling at the SF Zone was widely spaced, with no reserves or resources currently defined.

The SF Zone is interpreted to be a faulted extension of the JW Zone reserves and resources. Drill hole U17-1270 and 1274 were step-outs approximately 25 meters from previously reported hole U17-1248, which intersected 7.50 meters averaging 4.93 g/t Au and 23.54 g/t Ag, within a broad interval of 37.00 meters averaging 1.74 g/t Au and 16.80 g/t Ag. Drill hole U17-1274 intersected 8.0 meters averaging 12.28 g/t Au and 27.07 g/t Ag; mineralization is associated with a brecciated contact between intrusive and sedimentary rocks, associated with strong alteration and pyrite mineralization, surrounded by a sphalerite-rich halo (zinc sulphide). This mineralization style is typical of current reserves defined at Red Mountain. In drill hole U17-1270, the target horizon appears to be offset by a minor fault zone.

"Drill hole U17-1274 is an important intercept in the SF Zone, located a significant distance to the north of current reserves; additional drilling during 2017 will continue to prioritize and target this prospective area," said Robert McLeod, President and CEO of IDM Mining. "Ongoing underground drilling is also stepping out both up and down-dip of the Marc, NK, AV and JW Zones, with surface drilling targeting strike extensions to the 141 and Marc Zones."

Mineralization at Red Mountain is commonly gently folded, with local structural thickening; mineralization occurs in multiple blocks separated by strike-slip faults, with approximate 50 - 75 meters vertical displacement. Wide spaced drilling in the SF Zone, with local tight-spaced drilling near high-grade intercepts is the approach to understand the orientation and extent of mineralized zones and controlling host rocks. Drill hole U17-1279 intersected 1.0 meter of 7.98 g/t Au and 11.75 g/t Ag; follow-up drilling will target certain capping phases of intrusive rocks that result in significant thickening of mineralization, as observed at the JW and AV Zones to the south.

Complete results are as follows:

*Due to wide spaced drilling, true thickness is not known

Drill hole collar information and location maps, core photos along with plan views, cross-sections and longitudinal sections can be viewed at www.idmmining.com.

About Red Mountain

The 17,125 hectare Red Mountain Gold Project is located in northwestern BC, 15 km northeast of the Town of Stewart. IDM recently announced the results of a Feasibility Study for a high-grade, underground gold mine, which includes primarily bulk underground mining methods and the production of gold dor?(C) on site. The Project is advancing through the provincial and federal environmental assessment processes, with comprehensive, thorough, and ongoing consultation with Nisga'a Nation. The Company recently submitted its Project Application and Environmental Impact Statement to regulators and stakeholders.

Red Mountain is a porphyry-related hydrothermal gold system, located in the Stikine terrain. Gold mineralization is associated with, and partially hosted within an early to mid-Jurassic multi-phase intrusive complex, with associated volcanic and volcaniclastic rocks and sediments. Many gold mineralized zones occur on the property, including five mineralized zones with established resource estimates. The mineralized zones have been folded, and are often separated by dip-slip fault zones. Mineralization can vary in orientation from shallow to steeply dipping and are generally tabular. The Marc, AV and JW Zones range in widths from one to forty meters, averaging about sixteen meters in thickness. Gold and silver mineralization is associated with stockworks, disseminations and patches of coarse grained pyrite, surrounded by a pyrrhotite/sphalerite halo. Alteration facies includes strong quartz-sericite alteration.

Additional information, including the Company's NI 43-101 Technical Reports for the Red Mountain gold project, is available at www.idmmining.com and at www.sedar.com.

QA/QC AND QUALIFIED PERSON

Samples for the 2017 exploration program are cut in-half with a diamond saw, with one-half placed in sealed bags and shipped to ALS Labs Ltd. in Terrace, BC for sample preparation, with pulps subsequently shipped to Vancouver, BC for gold and multi-element ICP analysis. A Quality Control/Quality Assurance program, including the insertion of Standards and Blanks, has been implemented. The 2017 exploration program at Red Mountain is performed under the supervision of Rob McLeod, P.Geo, President and CEO of IDM Mining Ltd. and a 'Qualified Person' under NI 43-101. Mr. McLeod has reviewed and approved the technical content of this release.

ABOUT IDM MINING LTD.

IDM Mining Ltd. is a mineral exploration and development company based in Vancouver, BC, Canada. The Company's current exploration and development activities are focused on precious metals in British Columbia, with a primary focus on the high grade underground Red Mountain gold project.

ON BEHALF OF THE BOARD of IDM Mining Ltd.

Robert McLeod, President, CEO and Director

"Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release."

Forward-Looking Statements: Some statements in this news release contain forward-looking information or forward-looking statements for the purposes of applicable securities laws. These statements include, among others, statements with respect to the proposed exploration and development activities and their timing, resource estimates and potential mineralization. These statements address future events and conditions and, as such, involve known and unknown risks, uncertainties and other factors, which may cause the actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the statements. Such factors include, among others and in addition to those described elsewhere in this release, timing and success of future exploration and development activities, exploration and development risks, delays in obtaining or inability to obtain required government or other regulatory approvals, permits or financing, the risk of unexpected variations in mineral resources, grade or recovery rates, of failure of plant, equipment or processes to operate as anticipated, of accidents, labor disputes, and unanticipated delays in completing other development activities, the risk that estimated costs will be higher than anticipated and the risk that the proposed mine plan and recoveries will not be achieved, equipment breakdowns and bad weather, the timing and success of future exploration and development activities, exploration and development risks, mineral resources are not as estimated, title matters, third party consents, operating hazards, metal prices, political and economic factors, competitive factors and general economic conditions. In making the forward-looking statements, the Company has applied several material assumptions including, but not limited to, the assumptions that: required regulatory approval, permits and financing will be obtained; the proposed exploration and development will proceed as planned; with respect to mineral resource estimates, the key assumptions and parameters on which such estimates are based; that the proposed mine plan and recoveries will be achieved, that capital costs and sustaining costs will be as estimated, and that no unforeseen accident, fire, ground instability, flooding, labor disruption, equipment failure, metallurgical, environmental or other events that could delay or increase the cost of development will occur, and market fundamentals will result in sustained metals and minerals prices. The Company expressly disclaims any intention or obligation to update or revise any forward-looking statements whether as a result of new information, future events or otherwise except as otherwise required by applicable securities legislation.