The program was highlighted by the expansion of the Gryphon Zone of uranium mineralization on the Wheeler River property, and the discovery of a new zone of uranium mineralization on the Murphy Lake property.

Wheeler River Property

A total of 24,468 metres of drilling was completed in 34 drill holes during the summer program at Denison’s 60% owned Wheeler River project. Seven of the drill holes were designed to complete the 50 metre x 50 metre spaced drill pattern at Gryphon and outline the extent of the mineralization in the down-dip and down-plunge directions. The best result was in drill hole WR-604, for which chemical assay data is now available.

WR-604 intersected 6.3% U3O8 over 5.5 metres (779.0 to 784.5m), followed by 11.6% U3O8 over 1.0 metres (790.0 to 791.0m) – extending the zone of mineralization approximately 50 metres in the down-dip direction.

The Gryphon Zone of mineralization is now approximately 450 metres long in the down-plunge direction and 80 metres wide in the across-plunge direction. Thickness is variable due to the stacked nature of the lenses.

With the receipt of the final chemical assays from the drilling completed at the Gryphon Zone, the Company is working towards the completion of updated mineral resource estimates for the Wheeler River property before the end of 2015.

The updated technical report, which is being prepared in accordance with National Instrument 43-101, will include a mineral resource estimate at Gryphon, in addition to the Phoenix Deposit which is located roughly 3 kilometres to the southwest of Gryphon.

The Phoenix Deposit is currently estimated to contain an indicated mineral resource of 70.2M lbs U3O8 at a grade of 19.13% and an inferred mineral resource of 1.1M lbs U3O8 at a grade of 5.8%.

Twenty additional drill holes were completed in the general K North area surrounding the Gryphon Zone, to evaluate a variety of targets and identify additional mineralization. The best result from these targets was in drill hole WR-612, located 200 metres south of the unconformity mineralization identified on the WR-595/597 section during the winter 2015 exploration program. WR-612 intersected 2.4% U3O8 over 2.5 metres, approximately 25 metres below the unconformity.

The Wheeler River property is located between the McArthur River mine and Key Lake mill complex in the eastern portion of the Athabasca Basin in northern Saskatchewan. Denison is the operator and holds a 60% interest in the project. Cameco Corporation holds a 30% interest and JCU (Canada) Exploration Company Limited holds the remaining 10% interest.

Exploration Pipeline Properties

During the summer 2015 exploration program, Denison carried out exploration or geophysical surveys on nine properties, in addition to Wheeler River, within its extensive landholdings on the eastern side of the Athabasca Basin. Work on these pipeline exploration projects continues to deliver encouraging results.

At the Murphy Lake property, the first drill hole of the summer 2015 program intersected a new zone of uranium mineralization. Newly received assays for drill hole MP-15-03 returned 0.25% U3O8 over 6.0 metres from 270.0 to 276.0 metres. The mineralization at Murphy Lake is located at the sub-Athabasca unconformity and is associated with a zone of strong sandstone alteration including desilicification and clay over a hematite cap.

Basement rocks immediately below the mineralization consist of graphitic pelitic gneisses cut by faults. As the mineralization is interpreted to be horizontal and the drill holes are steeply inclined, the true thickness is expected to be at least 75% of the intersection length. Murphy Lake is a joint venture between Denison (58.9%1 and operator) and Eros Resource Corp. (41.1%1), formerly Anthem Resources Inc.

At the Waterbury Lake property, work was focused on the Oban target area. Ground geophysical surveys completed earlier in the year improved the geological interpretation of the area and highlighted several drill targets that were tested during the summer drilling program.

The best result was obtained from drill hole WL-425, which intersected 6.5 metres of elevated uranium from 239.5 to 246.0 metres that included 0.3% U3O8 over 0.5 metres and 0.1% U3O8 over 0.5 metres. Waterbury Lake is a joint venture between Denison (60%1 and operator) and the Korea Waterbury Uranium Limited Partnership (40%1).

At the 100% owned Crawford Lake property, a large zone of intense sandstone alteration along the CR-2 and CR-5 conductors was extended by the summer drilling program and has now been confirmed over a strike length of 2.9 kilometres.

While no significant uranium mineralization was intersected in 2015, the volume and tenor of the alteration system is encouraging and remains a priority for future exploration activities.