IDM Mining Announces Key Milestone Reached in the Environmental Assessment of the Red Mountain Underground Gold Project

VANCOUVER, BRITISH COLUMBIA--(Marketwired - March 31, 2017) - IDM Mining Ltd. (TSX VENTURE:IDM) ("IDM" or the "Company") is pleased to announce that the Environmental Assessment Office ("EAO"), with the support of provincial, federal, Aboriginal, and regional authorities, have approved and finalized the Application Information Requirements (AIR) for the proposed Red Mountain Underground Gold Project (the "Red Mountain Project"), located east of Stewart, BC.

The AIR sets out detailed guidelines for information to be included in IDM's Application for an Environmental Assessment Certificate / Environmental Impact Statement (the "Application/EIS"). This milestone is the last significant step prior to submission of the Application to the EAO and Canadian Environmental Assessment Agency ("CEAA"). The Application is scheduled to be submitted by IDM in Q2 2017. If the Application is determined by the EAO to include the information set out in the AIR, the legislated 180-day review period of the Application will begin.

In parallel with the preparation of the Project's Application/EIS, the Company is working on a Feasibility Study of the Red Mountain Project. The study is being led by JDS Energy and Mining Inc. and is supported by a number of specialist engineering firms. The Feasibility Study remains on track for completion in Q2 2017.

The approval of the AIR follows several months of public engagement, technical review, and consultation, including: a public open house in Stewart, a public comment period, community open houses in the Nisga'a Villages of Gitlaxt'aamiks and Gitwinksihlkw, and several focused, technical discussions with Nisga'a Nation representatives and consultants.

"This is a key step in the environmental assessment of the Red Mountain Project," said Michael McPhie, Executive Chairman of IDM. "We are very happy with our progress in advancing this aspect of the Project in a timely and efficient manner. We want to acknowledge the good work and professionalism of the BC EAO representatives, the BC EAO-led Advisory Working Group members, and Nisga'a Nation who have all facilitated the completion of this key step in the process. The environmental assessment and permitting timeline for the Red Mountain Project remains fully on track, and we look forward to submitting the Application/EIS later this spring. We are now able to focus our efforts on the development of the Application/EIS with the confidence that the information we will be providing will be satisfactory and anticipated by regulators and Nisga'a Nation."

A copy of the AIR document can be found on BC EAO's Project Information and Collaboration web site:

https://projects.eao.gov.bc.ca/p/red-mountain-underground-gold/detail

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 which is progressing through the BC and Canadian environmental assessment process. Further information can be found on the Company's website at www.IDMmining.com

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, potential mineralization and timing for the filing of the Application/EIS and completion of the Feasibility Study. 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.