Mr. Robert McLeod reports

IDM MINING INTERSECTS 20.29 G/T AU AND 68.74 G/T AG OVER 8.0 METERS TRUE WIDTH AT THE RED MOUNTAIN GOLD PROJECT

IDM Mining Ltd. has released assays from an additional 10 underground core holes completed at the Red Mountain gold project, located 15 kilometres east of Stewart, B.C. These results are from the continuing phase I drilling program.

Highlights from the recent underground drill results (capped) include:

• U16-1194: 23.13-metre true width at 5.81 grams per tonne gold and 16.11 g/t silver, AV zone infill and metallurgical hole;
• U16-1200: 7.44 m true width at 12.18 g/t Au and 19.04 g/t Ag, JW zone infill;
• U16-1202: 17.81 m true width at 6.45 g/t Au and 60.70 g/t Ag, JW zone infill and metallurgical hole;
• U16-1204: 15.43 m true width at 10.97 g/t Au and 9.18 g/t Ag, Marc zone infill and metallurgical hole;
• U16-1205: eight m true width at 20.29 g/t Au and 68.74 g/t Ag, Marc zone infill and metallurgical hole.

This batch of drill results is primarily infill holes to gather data for continuing feasibility study work, including metallurgical, geotechnical and hydrological data, as well as to potentially upgrade inferred and indicated resources to higher categories.

"These results confirm the substantial widths and robust grades at Red Mountain," said Robert McLeod, president and chief executive officer of IDM Mining. "Our underground drill crews at Red Mountain are currently wrapping up the final resource expansion holes from the 2016 program, with additional assay results to be announced through the remainder of the year, including surface drilling from Lost Valley, 141 and Brad zones."

Drill holes U16-1194 and 1196 tested a thick portion of the AV zone, infilling a 50 m gap between historic holes. Material was also collected for metallurgical testwork, and for geotechnical and groundwater hydrology. U16-1194 intersected 23.13 m true width averaging 5.81 g/t Au and 16.11 g/t Ag, with U16-1196 intersecting 22.0 m true width averaging 3.05 g/t Au. These holes correlate well with estimated grade and thickness of the AV zone in this area of the deposit. Drill hole U16-1195 tested a gap in the narrower, downdip tail to the AV zone.

The primary purposes of drill holes U16-1197, 1198 and 1199 were for geotechnical and groundwater hydrology studies, in particular, to confirm the location of a postmineralization strike-slip fault that separates the AV and JW zones and to assess overall host rock competency.

On Section 1550N, drill holes U16-1200 and 1202 targeted inferred resources of the JW zone and to collect material for metallurgical testwork. U16-1200 intersected 7.44 m true width averaging 12.18 g/t Au and 19.04 g/t Ag, including 2.49 m true width averaging 26.63 g/t Au and 23.48 g/t Ag. Drill hole U16-1202 intersected 17.81 m true width averaging 6.45 g/t Au and 60.70 g/t Ag, including 3.48 m true width averaging 12.98 g/t Au and 181.15 g/t Ag. High-grade silver was encountered in this intercept, which extends the JW zone farther updip from historic intercepts.

Drill holes U16-1204 and 1205 were infill and metallurgical holes targeted the north end of the Marc zone, adjacent to the fault that offsets mineralization to the AV zone farther north. U16-1204 intersected 15.43 m true width averaging 10.97 g/t Au (capped) and 9.18 g/t Ag; this included 0.80 m averaging 99.50 g/t Au and 72.30 g/t Ag, as well as one m averaging 101.50 g/t Au and 24.40 g/t Ag. These high-grade gold values were capped to 55.00 g/t Au.

Complete results are as shown in the table.

                RED MOUNTAIN DRILL RESULTS

                                                   True
Hole              From         To     Length      width
                    (m)        (m)        (m)        (m)

U16-1194         88.13     113.00      24.87      23.13
U16-1195        101.00     103.00       2.00       2.00
U16-1196         87.00     109.00      22.00      22.00
including        93.00      99.00       6.00       6.00
U16-1197         77.00      79.00       2.00       2.00
                 84.50      86.50       2.00       2.00
                 89.00      90.00       1.00       1.00
U16-1198         92.00     100.00       8.00       6.40
                106.69     107.27       0.58       0.46
                134.00     135.00       1.00       0.80
                163.00     164.00       1.00       0.80
U16-1199         55.00      58.00       3.00       2.46
                106.00     110.00       4.00       3.28
                113.50     120.00       6.50       5.33
including       113.50     115.50       2.00       1.64
U16-1200        150.00     158.00       8.00       7.44
including       151.00     154.00       3.00       2.49
U16-1202        153.53     174.00      20.47      17.81
including       167.00     171.00       4.00       3.48
U16-1204         20.00      23.00       3.00       3.00
                 53.57      69.00      15.43      15.43
including        55.20      56.00       0.80       0.80
including        62.00      63.00       1.00       1.00
U16-1205         23.00      59.00      36.00      36.00
                 37.00      45.00       8.00       8.00
                 71.00      73.50       2.50       2.50

                                          Uncapped   Uncapped
Hole                     Au(i)      Ag(i)       Au         Ag
                       (g/t)      (g/t)       (g/t)      (g/t)

U16-1194               5.81      16.11
U16-1195               4.74       1.60
U16-1196               3.05       6.11
including              5.28       6.87
U16-1197               3.94       1.31
                       2.60       4.35
                       3.35      11.15
U16-1198               2.02       1.37
                       6.77      20.50
                       4.11       1.62
                      12.80       5.84
U16-1199               3.16       0.85
                       3.82      16.86
                       4.01       0.97
including              8.07       2.00
U16-1200              12.18      19.04
including             26.63      23.48
U16-1202               6.45      60.70        6.45     100.08
including             12.98     181.15       12.98     382.70
U16-1204               7.76       5.23
                      10.97       9.18       16.29       9.18
including             55.00      72.30       99.50      72.30
including             55.00      24.40      101.50      24.40
U16-1205               6.27      33.70
                      20.29      68.74
                       5.63       5.46

(i) Assays capped at 55.0 g/t Au and 220 g/t Ag.
(ii) Drilled intervals estimated using approximate three g/t 
cut-off for underground mining.
(iii) In many intercepts, 10- to 20-centimetre intervals of 
whole core were collected for grind and rock mechanical 
properties tests; these intervals were assigned a zero (0.0 
g/t Au and Ag) grade during compositing.

Drill hole collar information and location maps, core photos, and sample cross-sections can be viewed at the company's website.

About Red Mountain

The 17,125-hectare Red Mountain gold project is located in northwestern British Columbia, 15 kilometres northeast of the town of Stewart. IDM is advancing a feasibility study for a high-grade underground gold mine, which envisions primarily bulk underground mining methods. Additionally, the project is advancing through the provincial and federal environmental assessment process, with continuing consultation with the Nisga'a First Nation government.

On April 4, 2016, the company announced an updated mineral resource estimate reported at three g/t Au cut-off for the Red Mountain gold project.

                         UPDATED MINERAL RESOURCE ESTIMATE

Classification              Tonnage         Au         Ag         Au         Ag
                                          (g/t)      (g/t)       (oz)       (oz)

Measured                    847,200       9.38         34    255,400    920,700
Indicated                   794,600       7.29         18    186,100    459,100
Measured plus indicated   1,641,800       8.36         26    441,500  1,379,800
Inferred                    548,100       6.10          9    107,500    153,700

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 multiphase 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 five mineralized zones (Marc, AV, JW, 141 and 132) have been folded and are often separated by dip-slip fault zones. The mineralized zones vary in orientation from shallow to steeply dipping and are generally tabular. The Marc, AV and JW zones vary in widths from one to 40 m, averaging about 15 m 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 include strong quartz-sericite alteration.

Additional information, including the company's NI 43-101 technical reports for the Red Mountain gold project, is available at the company's website and SEDAR.

Quality assurance/quality control and qualified person

Samples for the 2016 exploration program are cut with a diamond saw, and placed in sealed bags and shipped to ALS Labs Ltd. in Terrace, B.C., for sample preparation, with pulps subsequently shipped to Vancouver, B.C., for gold and multielement ICP analysis. A QA/QC program, including the insertion of standards and blanks, has been implemented. The 2016 exploration program is performed under the supervision of Mr. McLeod, a qualified person under National Instrument 43-101. Mr. McLeod has reviewed and approved the technical content of this release.

We seek Safe Harbor.