High-Grade Unconformity Mineralization Near the Gryphon Deposit 

 

TORONTO, ON - Denison Mines Corp. reported the extension of new high-grade unconformity-hosted uranium mineralization located up-dip and approximately 250 meters along strike to the northeast of the basement-hosted Gryphon deposit, on the Company's 60% owned Wheeler River project. Preliminary radiometric equivalent grades ("eU3O8") from drill hole WR-670D2 are highlighted by an interval of 4.3% eU3O8 over 4.3 meters, from mineralization occurring immediately above the sub-Athabasca unconformity. This result adds to previous unconformity mineralized intercepts that include 5.0% eU3O8 over 4.7 meters in drill hole WR-689D3 and 1.2% eU3O8 over 1.4 meters in drill hole WR-690D3 (see Denison's press release dated August 30, 2017). The new zone of "E series" unconformity mineralization now extends approximately 80 meters horizontally along the unconformity and remains open along strike to the northeast and southwest.

In addition, after nearly six months of field activities, Denison is pleased to report that the summer 2017 drilling program at Wheeler River has now been concluded, following the completion of a further 30 drill holes totaling 12,466 meters. Preliminary radiometric grades for these results are reported herein and represent a strong finish, to an extended summer exploration program at Wheeler, with continued exploration success on multiple fronts. Importantly, these results also represent the final batch of drill holes to be completed ahead of the planned update to the Company's resource estimate for the Gryphon deposit and the Wheeler River project.