Denison Announces Significant Increase to Summer 2017 Drilling Program at Wheeler River

TORONTO, ONTARIO--(Marketwired - Sept. 12, 2017) - Denison Mines Corp. ("Denison" or the "Company") (TSX:DML)(NYSE MKT:DNN)(NYSE American:DNN) is pleased to announce a significant increase in the number of drill holes to be completed during the summer 2017 exploration program on the Company's 60% owned Wheeler River project. The summer 2017 program is now expected to continue into October and will be increased by approximately 16 drill holes (6,500 metres). As a result of the increase, the summer exploration program is now expected to include a total of approximately 62 drill holes (28,000 metres).