Klondex Mines Underground Development Yields 1,465 Tons of 32.7 g/t (0.95 opt) Gold in July

ELKO, NV and VANCOUVER, BC--(Marketwired - Sep 12, 2013) - Klondex Mines Ltd. (TSX: KDX) (OTCQX: KLNDF), a Nevada gold exploration and development company, today reported that its underground development program, targeting the Joyce and Vonnie structures within the Main Zone of its Fire Creek project, yielded 1,329 tonnes (1,465 tons) of mineralized material in July at an average grade of 32.7 g/t (0.95 opt) gold. Underground development at the Fire Creek project over the last three months has yielded 3,249 tonnes (3,582 tons) of mineralized material averaging 75.4 g/t (2.20 opt) Au.

Klondex continued to develop on the Joyce (5370N and 5400S) structure and on the Vonnie (5370N and 5400S) structure during July. A total of 240 samples were taken from these work areas and submitted for assay during July. Gold grades ranged from 0.2 g/t Au to 400 g/t Au (0.005 opt Au to 11.690 opt Au) over a vein width ranging from of 0.1 m to 0.7 m (0.2 ft to 2.4 ft).

Paul Huet, Klondex President and CEO, stated, "Through our underground development program, we continue to see very encouraging gold grades and are gaining an excellent understanding of the geology, structure and gold mineralization of the Fire Creek deposit. We've made tremendous progress over the past year as a direct result of our dedicated team, and I'm thankful for their devotion to Klondex and to advancing the Fire Creek project."

Sampling a given face is conducted after the face location has been measured, photographed, and mapped in detail. Continuous rock-chip channel samples are then collected by Klondex staff in 11" x 17" sample bags from the footwall, vein, and hanging wall. Salient features including sample number, channel length, location on face, rock type, and alteration are documented. Samples are sent to SGS Mineral Services Division lab in Elko, Nevada, an independent laboratory, for gravimetric fire assay analysis with blanks and standards.

The technical information contained in this press release has been approved by Steven L. McMillin, CPG-11031 (American Inst. of Prof. Geol.), Chief Geologist for Klondex Mines Ltd., as a non-independent Qualified Person for the purposes of National Instrument 43-101.

About Klondex Mines Ltd. (www.klondexmines.com)
Klondex Mines is focused on the exploration and development of its Fire Creek gold deposit in North-Central Nevada. Fire Creek is a compelling gold project located in a mining-friendly jurisdiction, near major producers, power, transportation, mining infrastructure and its milling facility. At September 12, 2013, Klondex had 65.5M shares issued and outstanding and 88.4M shares, fully diluted.

This news release contains certain information that may constitute forward-looking information under applicable Canadian securities legislation, including information about the magnitude and quality of the Fire Creek Project the results of exploration and metallurgical sampling at the Fire Creek Project, the Company's intention and ability to monetize mineralized material, timing of the updated mineral resource estimate at the Fire Creek Project and the bulk sampling program. This forward-looking information entails various risks and uncertainties are based on current expectations, and actual results may differ materially from those contained in such information. These risks and uncertainties include, but are not limited to the risks and hazards associated with environmental compliance and permitting for its underground operations, 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 factors which would make a mineral deposit commercially viable are present. 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 available at www.sedar.com. 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.