Denison Reports New High-Grade Uranium Discovery on the Waterbury Lake Property

TORONTO, ONTARIO--(Marketwired - Aug. 1, 2017) - Denison Mines Corp. ("Denison" or the "Company") (TSX:DML)(NYSE MKT:DNN)(NYSE American:DNN) is pleased to report a new high-grade uranium intersection in basement rocks from the first hole completed as part of the summer 2017 drilling program at the Waterbury Lake property. Drill hole WAT-17-443 intersected 1.1% eU3O8 over 0.8 metres (from 296.9 to 297.7 metres) approximately 1.5 kilometres to the northeast of the property's J Zone uranium deposit. The high-grade mineralization occurs immediately below a broader 10.3 metre mineralized interval (from 282.8 to 293.1 metres) with an average grade of 0.15% eU3O8. The mineralization is open in all directions and follow-up drilling is presently underway. Results are reported as preliminary radiometric equivalent grades ("eU3O8") derived from a calibrated downhole total gamma probe. The Company subsequently reports definitive assay grades following sampling and chemical analysis of the mineralized drill core.