Denison Announces 88% Increase in Indicated Resources at Wheeler River With Updated Mineral Resource Estimate for the Gryphon Deposit

TORONTO, ONTARIO--(Marketwired - Jan. 31, 2018) - Denison Mines Corp. ("Denison" or the "Company") (TSX:DML)(NYSE MKT:DNN)(NYSE American:DNN) is pleased to announce an 88% increase in the Indicated Mineral Resources estimated for the Wheeler River project. Denison is also pleased to announce it has increased its interest in the Wheeler River project during 2017 from 60% to 63.3% in accordance with an agreement with its Wheeler River Joint Venture partners, as previously announced on January 10, 2017. The updated mineral resource estimate for Wheeler River is highlighted by a significant increase in the estimated mineral resources for the property's basement-hosted Gryphon uranium deposit.