Denison Announces High Grade Uranium Drill Intersections at Mann Lake and Wheeler Rive

Skyharbour's Neighbor Denison Announces High Grade Uranium Drill Intersections at Mann Lake

About Skyharbour's Mann Lake Project

Skyharbour Resources (TSX-V: SYH) owns 60% interest in the Mann Lake Uranium Project located in the eastern Athabasca Basin in northern Saskatchewan. The Mann Lake property is ajacent to the Mann Lake Joint Venure operated by Cameco (52.5%) with partners Denison Mines (30%) Areva (17.5%). Skyharbour recently carried out a ground-based EM survey focused on a zone where a favourable, 2 km long aeromagnetic low coincides with possible basement conductor trends indicated by prior EM surveys. The survey was successful in confirming the presence of a broad, NE-SW trending corridor of conductive basement rocks which are probably graphitic metapelites. Skyharbour's Mann Lake project is drill ready.

Mann Lake - Athabasca Basin

Denison Mines February 4, 2015 News Release:

TORONTO, ONTARIO--(Marketwired - Feb. 4, 2015) - Denison Mines Corp. ("Denison" or the "Company") (TSX:DML)(NYSE MKT:DNN) is pleased to report a successful start to its winter exploration programs with high grade uranium drill intersections on two different properties, Mann Lake and Wheeler River, in the Eastern Athabasca Basin. Mann Lake is located 20 kilometres southwest of the McArthur River mine and five kilometres north of Wheeler River and is a joint venture (Denison 30%) with Cameco Corp (52.5% and operator) and Areva Resources Canada (17.5%). Wheeler River is a joint venture (Denison 60% and operator) with Cameco Corp (30%) and JCU (Canada) Exploration Company, Limited (10%).

"We are encouraged by the high grade intersections at Mann Lake, Denison's most recent addition to its Athabasca Basin exploration portfolio, and by the additional high grade intersections at Wheeler River as we focus on expanding our Gryphon discovery", commented Ron Hochstein, CEO of Denison.

Mann Lake

Drilling at Mann Lake in 2015 is designed to explore for extensions of uranium mineralization intersected in drill holes MN-060 (2.94% U₃O₈ over 4.8 metres) and MN-065 (4.8% U₃O₈ over 1.0 metres) in 2014. Uranium in these drill holes is located along the sub-Athabasca unconformity at its intersection with a fault zone. Two of 12 planned drill holes have been completed in the current program. Drill hole MN-066-01 located 300 metres along strike south of MN-060, intersected 9.8% eU₃O₈ over 3.5 metres - the best result to date on the Mann Lake property. As MN-066-01 is the furthest drill hole to the south on the zone, mineralization is open beyond it. The other drill hole, MN-061-01, located 900 metres north of MN-060 intersected weakly elevated radioactivity immediately beneath the unconformity. The drilling results are summarized in Table 1. Figure 1 shows the location of the Mann Lake drill holes in plan view. As the drill holes are oriented steeply, and the mineralization is approximately horizontal, the true thickness is expected to be at least 80% of the intersection lengths.

Wheeler River

The winter 2015 drill program at Wheeler River is designed to extend the Gryphon zone of basement hosted uranium mineralization discovered in 2014. Mineralization at Gryphon is hosted in basement gneisses, ranging from 100 to 250 metres below the sub-Athabasca unconformity. Prior to the start of the current drill program the zone was 350 metres long (along the plunge) by 60 metres wide (across the plunge). The zone consists of multiple stacked lenses with variable thicknesses that plunge to the northeast and remain open both up and down-plunge. The initial drill holes of this year's program are designed to test for extensions of mineralization in both the up-plunge and down-plunge directions. Four of a planned 22 drill holes have been completed so far and the highlight is drill hole WR-584B on the up-plunge end of the zone, which intersected 9.0% eU₃O₈ over 4.6 metres. WR-584B extends the Gryphon zone approximately 50 metres. Two drill holes targeting the down-plunge extension of mineralization have also been completed. WR-582 and WR-583 intersected 2.9% eU₃O₈ over 2.4 metres and 2.8% eU₃O₈ over 2.4 metres, respectively. These holes extend the Gryphon zone approximately 50 metres down-plunge. A fourth hole, WR-577D1 was also completed at the up-plunge end of the zone, approximately 50 metres from WR-584B and it intersected several narrow, weak intervals of mineralization, the best of which was 0.3% eU₃O₈ over 2.0 metres. The drill results are summarized in Table 1. Figure 2 shows the location of the Gryphon zone drill holes on an inclined longitudinal section. As the drill holes are oriented steeply toward the northwest and the mineralization dips moderately to the southeast, the true thickness is expected to be approximately 75% of the intersection lengths.

Table 1 - Winter 2015 Initial Drilling Results

Qualified Person

The disclosure of a scientific or technical nature contained in this news release was prepared by Steve Blower, P.Geo., Denison's Vice President, Exploration, who is a Qualified Person in accordance with the requirements of NI 43-101. For a description of the quality assurance program and quality control measures applied by Denison, please see Denison's Annual Information Form dated March 14, 2014 filed under the Company's profile on SEDAR at www.sedar.com.

About Denison

Denison is a uranium exploration and development company with interests in exploration and development projects in Canada, Zambia, Mali, Namibia and Mongolia. Including its 60% owned Wheeler project, which hosts the high grade Phoenix uranium deposit, Denison's exploration project portfolio consists of numerous projects covering over 470,000 hectares in the eastern Athabasca Basin region of Saskatchewan. Denison's interests in Saskatchewan also include a 22.5% ownership interest in the McClean Lake joint venture, which includes several uranium deposits and the McClean Lake uranium mill, one of the world's largest uranium processing facilities, plus a 25.17% interest in the Midwest deposit and a 60% interest in the J Zone deposit on the Waterbury property. Both the Midwest and J Zone deposits are located within 20 kilometres of the McClean Lake mill. Internationally, Denison owns 100% of the conventional heap leach Mutanga project in Zambia, 100% of the uranium/copper/silver Falea project in Mali, a 90% interest in the Dome project in Namibia, and an 85% interest in the in-situ recovery projects held by the GSJV in Mongolia.

Denison is engaged in mine decommissioning and environmental services through its DES division and is the manager of UPC, a publicly traded company which invests in uranium oxide and uranium hexafluoride.