Klondex Encounters High-Grade Mineralization at Hatter Graben; Midas Mill Recovery of Hollister Ore Improving

VANCOUVER, BC--(Marketwired - November 20, 2017) - Klondex Mines Ltd. (TSX: KDX) (NYSE American: KLDX) ("Klondex" or the "Company") is pleased to provide the initial results from the 2017 surface exploration drill program at the Hatter Graben zone near its Hollister Mine ("Hollister") and report on progress made at the Midas mill regarding recovery of Hollister ore. Both Hollister and the Company's Midas mill are located in northern Nevada, USA.

Hatter Graben Surface Drilling Highlights: (see TABLE 1 for complete results)

• H17-001: 1.53 opt AuEq over 3.1 ft, or 52.4 g/t over 0.9 m
• H17-005: 1.18 opt AuEq over 6.0 ft, or 40.5 g/t over 1.8 m
• H17-004: 0.87 opt AuEq over 2.5 ft, or 29.7 g/t over 0.8 m
• H17-001: 0.74 opt AuEq over 6.5 ft, or 25.4 g/t over 2.0 m
  -- Including 1.25 opt AuEq over 2.9 ft, or 42.9 g/t over 0.9 m

KEY POINTS:

Assays were received for the first five surface core holes at Hatter Graben. These are the first assays from an 11 hole drill program which was designed to infill drilling completed during 2008. The intent of this drill program is to develop an initial inferred resource at Hatter Graben. (Figure 1)

Drilling intersected several zones of multiple sub parallel veins similar to features encountered in 2008. Moreover, the results have extended the vein system down dip approximately 200 ft from the known mineralization. We now have a total of approximately 1,400 ft of vertical height of mineralized veins and the ongoing drilling is intended to further extend mineralization east along strike. Mineralization at Hatter Graben remains open in all directions. Drilling continues and is scheduled to be completed in early December. After which, the Company expects to receive final assays from the remaining six core holes by year end and publish an initial resource during the first quarter of 2018. (Figure 2)

Additionally, drill results have demonstrated that Hatter Graben is comprised of more competent rock compared to the Hollister mine. The host rock in the Hollister mine is clay rich and contains marginal ground conditions. The preferable ground conditions at Hatter Graben should allow for better vein development, superior dilution control and makes the more efficient long-hole stoping mining method a viable option.