Klondex Set to Join Russell 3000(R) Index VANCOUV

VANCOUVER, BC --(Marketwired - June 23, 2017) - Klondex Mines Ltd. ( TSX : KDX ) ( NYSE MKT : KLDX ) ("Klondex" or the "Company") is pleased to announce it has been added to the broad-market Russell 3000® Index at the conclusion of the Russell indexes annual reconstitution, effective after the US market opens on June 26, according to a preliminary list of additions posted June 9.

Annual Russell indexes reconstitution captures the 4,000 largest US stocks as of the end of May, ranking them by total market capitalization. Membership in the US all-cap Russell 3000® Index, which remains in place for one year, means automatic inclusion in the small-cap Russell 2000® Index as well as the appropriate growth and value style indexes. FTSE Russell determines membership for its Russell indexes primarily by objective, market-capitalization rankings and style attributes.

Russell indexes are widely used by investment managers and institutional investors for index funds and as benchmarks for active investment strategies. Approximately $8.4 trillion in assets are benchmarked against Russell's US indexes. Russell indexes are part of FTSE Russell, a leading global index provider.

For more information on the Russell 3000® Index and the Russell indexes reconstitution, go to the "Russell Reconstitution" section on the FTSE Russell website .

About Klondex Mines Ltd. ( www.klondexmines.com ):

Klondex is a well-capitalized, junior-tier gold and silver mining company focused on exploration, development, and production in a safe, environmentally responsible, and cost-effective manner. The Company has 100% interests in three producing mineral properties: the Fire Creek Mine and the Midas Mine and ore milling facility, both of which are located in the state of Nevada, USA, and the True North Gold Mine and mill in Manitoba, Canada. The Company also has 100% interests in two recently acquired projects, the Hollister mine and the Aurora mine and ore milling facility, also located in Nevada, USA.

About FTSE Russell:

FTSE Russell is a leading global index provider creating and managing a wide range of indexes, data and analytic solutions to meet client needs across asset classes, style and strategies. Covering 98% of the investable market, FTSE Russell indexes offer a true picture of global markets, combined with the specialist knowledge gained from developing local benchmarks around the world.

FTSE Russell index expertise and products are used extensively by institutional and retail investors globally. Approximately $12.5 trillion is currently benchmarked to FTSE Russell indexes. For over 30 years, leading asset owners, asset managers, ETF providers and investment banks have chosen FTSE Russell indexes to benchmark their investment performance and create investment funds, ETFs, structured products and index-based derivatives. FTSE Russell indexes also provide clients with tools for asset allocation, investment strategy analysis and risk management.

A core set of universal principles guides FTSE Russell index design and management: a transparent rules-based methodology is informed by independent committees of leading market participants. FTSE Russell is focused on index innovation and customer partnership applying the highest industry standards and embracing the IOSCO Principles. FTSE Russell is wholly owned by London Stock Exchange Group.

For more information, visit www.ftserussell.com .

Cautionary Note Regarding Forward-looking Information

This news release contains certain information that may constitute forward-looking information or forward-looking statements under applicable Canadian and United States securities legislation (collectively, "forward-looking information"), including but not limited to the addition of the Company to the Russell 3000 Ò Index and the timing thereof. This forward-looking information entails various risks and uncertainties that are based on current expectations, and actual results may differ materially from those contained in such information. These uncertainties and risks include, but are not limited to, the strength of the global economy; the price of gold; operational, funding and liquidity risks; the degree to which mineral resource estimates are reflective of actual mineral resources; the degree to which mineral reserve estimates are reflective of actual mineral reserves; the degree to which factors which would make a mineral deposit commercially viable are present; the risks and hazards associated with underground operations; and the ability of Klondex to fund its substantial capital requirements and operations. Risks and uncertainties about the Company's business are more fully discussed in the Company's disclosure materials filed with the securities regulatory authorities in Canada and United States available at www.sedar.com and www.sec.gov , respectively. Readers are urged to read these materials. Klondex assumes no obligation to update any forward-looking information or to update the reasons why actual results could differ from such information unless required by law.