Denison Intersects 5.0% EU 3O8 over 4.7 Metres at the Unconformity as Definition and Expansion Drilling Continues ON the Gryphon Deposit at Wheeler River
Denison Mines Corp.
1100 – 40 University Ave
Toronto, ON M5J 1T1
www.denisonmines.com
@DenisonMinesCo
PRESS RELEASE
DENISON INTERSECTS 5.0% eU 3O8 OVER 4.7 METRES AT THE
UNCONFORMITY AS DEFINITION AND EXPANSION DRILLING CONTINUES
ON THE GRYPHON DEPOSIT AT WHEELER RIVER
Toronto, ON – August 30, 2017 Denison Mines Corp. (“Denison” or the “Company”) (TSX: DML) (NYSE
MKT: DNN) (NYSE American: DNN) is pleased to report the intersection of new high-grade unconformity-
hosted uranium mineralization in drill hole WR-689D 3 approximately 250 metres along strike to the
northeast and 200 metres up-dip of the Gryphon depo sit, on the Company’s 60% owned Wheeler River
project. Preliminary radiometric equivalent probe results (“eU 3O8”) from drill hole WR-689D3 are highlighted
by an interval of 5.0% eU 3O8 over 4.7 metres, including 8.5% eU 3O8 over 2.7 metres, from mineralization
occurring immediately above the sub-Athabasca uncon formity that is comprised of massive to semi-
massive uraninite (pitchblende) associated with hydrothermal hematite and clay alteration.
Denison is also pleased to report that a further te n drill holes have been completed within the D seri es of
mineralized lenses, which occur entirely outside of the current resources estimated for the Gryphon deposit.
The results continue to exhibit thick high-grade mi neralized intervals as drilling focuses on expandin g
mineralization outwards, on an approximate 25 metre drill spacing, from the previously released result s in
drill holes WR-641 (5.3% U 3O8 over 11.0 metres) and WR-633D3 (1.3% U 3O8 over 3.0 metres, plus 3.3%
U3O8 over 13.5 metres, and 6.2% U 3O8 over 2.5 m).
Today's news is highlighted by the following:
• Discovery of new high-grade unconformity-hosted mi neralization in drill holes WR-689D3 (5.0% eU 3O8
over 4.7 metres) and WR-690D3 (1.2% eU 3O8 over 1.4 metres) immediately up-dip of previously
intersected basement mineralization that includes d rill hole WR-507D2 (19.30% U 3O8 over 1.0 metre)
and drill hole WR-646 (6.20% U 3O8 over 2.5 metres).
• The mineralization occurring at the unconformity i s open along strike in both directions, and togethe r
with the high-grade mineralization previously disco vered in the upper basement has been termed the
“E series” of lenses, representing a new high priority target area for resource expansion
• A further ten drill holes have been completed with in the D series lenses, with results continuing to
include thick and high-grade mineralized intervals, as drilling expands the mineralized zone outwards
from drill holes WR-641 and WR-633D3. Detailed res ults from the latest drill holes are provided in
Table 1, and include the following highlights:
o 4.8% eU 3O8 over 3.7 metres in drill hole WR-694
o 3.8% eU 3O8 over 3.7 metres in drill hole WR-690D2
o 2.0% eU 3O8 over 5.2 metres in drill hole WR-657D1
o 6.4% eU 3O8 over 1.0 metre in drill hole WR-690D1
• Two drill holes testing for an extension of minera lization outside and near the fringes of the curren t
resources estimated for the Gryphon Deposit’s A ser ies lenses successfully intersected high-grade
mineralization:
o 1.5% eU 3O8 over 4.6 metres in drill hole WR-638D4
o 1.3% eU 3O8 over 3.6 metres in drill hole WR-682D1
• Six additional infill and delineation drill holes have been completed on the Gryphon Deposit’s A, B and
C series lenses. Detailed results from the latest d rill holes are provided in Table 2, and include the
following highlights:
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o 1.3% eU 3O8 over 21.8 metres in drill hole WR-572D1, including 3.9% eU 3O8 over 5.3 metres
o 5.8% eU 3O8 over 5.4 metres in drill hole WR-564D3
o 1.8% eU 3O8 over 3.9 metres in drill hole WR-564D3
David Cates, Denison’s President and CEO, commented , “The notable high-grade mineralization
intersected at the unconformity, immediately northeast of the Gryphon deposit, presents our Saskatoon
based exploration team with a new and exciting targ et for additional exploration – with the potential for
further drilling to continue to expand resources at Gryphon. Coupled with a steady stream of impressive
high-grade intersections within the basement-hosted D series lenses, the prospect of significant growth
in our estimate of resources for the Gryphon deposi t continues to increase as we work towards
completing an updated resource estimate following the completion of the summer drilling program.”
Emergence of the E Series Lenses
The E series lenses, previously reported in several instances as mineralization along the A or B serie s
plane, occur as a series of closely spaced stacked lenses at or immediately below the unconformity (within
the basement) approximately 50 metres along strike to the northeast and 50 to 200 metres up-dip of the
current resources estimated for the Gryphon deposit . Collectively the E series lenses measure
approximately 350 meters along strike (southwest to northeast) and up to 40 meters along dip (moderately
toward the southeast), with individual lenses varyi ng in interpreted true thickness from approximately 1 to
3 metres.
The discovery and initial delineation of the minera lization comprising the E series lenses was a resul t of
drill holes designed primarily to test for D series mineralization, which occurs deeper in the basemen t.
These drill holes resulted in a series of mineraliz ed basement intersections near the unconformity, wh ich
include the following previously reported results ( see Denison’s Press Releases dated May 26, 2016 and
November 17, 2016):
o 19.30% U 3O8 over 1.0 metres in drill hole WR-507D2
o 6.20% U 3O8 over 2.5 metres in drill hole WR-646
o 1.61% U 3O8 over 1.0 metres in drill hole WR-671
o 1.38% U 3O8 over 1.0 metres in drill hole WR-675
The new unconformity mineralization intersected in WR-689D3 and WR-690D3 is located in sandstone
‘wedges’ produced as a result of reverse faulting of the basement units below. The unconformity-hosted
mineralization is interpreted to be the up-dip unco nformity expression of the previously discovered
basement lenses and are assumed to be continuous to semi-continuous in nature. The mineralization
remains open along strike in both directions along the unconformity to the northeast and southwest whe re
similar geologic settings exist with mineralized basement intersections below.
A significant zone of structural disruption, bleach ing and clay alteration, including dravite, was not ed
immediately overlying the mineralization within the sandstone in drill holes WR-689D3 and WR-690D3.
These features are typical of high-grade unconformi ty-hosted uranium deposits such as Phoenix, which
occurs approximately 3 kilometres to the southeast on the Wheeler River property.
Future exploration of the E series lenses will focu s on evaluating the continuity of the basement lens es as
well as their unconformity expression using drill o rientations and spacing appropriate to the style of
mineralization being tested and evaluated.
Continued Expansion of the D Series Lenses
The summer 2017 drilling within the D series lenses has focussed on testing around drill holes WR-641
(5.3% U 3O8 over 11.0 metres) and WR-633D3 (1.3% U 3O8 over 3.0 metres, 3.3% U 3O8 over 13.5 metres,
and 6.2% U 3O8 over 2.5 m) on an approximate 25 metre spacing, wi th the objective of adding indicated or
inferred resources to the Gryphon deposit. The summer 2017 results, as provided in Table 1, include thick
and high-grade intersections in all directions, whi ch indicate continued expansion of this high-grade
mineralization. The mineralized zone remains open i n numerous areas and now occurs over an area of
approximately 70 meters along strike and 200 meters along dip, with interpreted true thicknesses varyi ng
between approximately 2 and 20 metres.
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To date, the delineation drilling within the D seri es lenses (on a 25 metre spacing), has only tested
approximately 50 to 70 metres of strike length within the D series plane. A further approximate 250 metres
of known D series lenses strike remains to be evalu ated at this tighter drill spacing. Furthermore, th e D
series lenses remain completely open to the northeast and southwest.
Additional Extension of the A Series Lenses
Drill hole WR-638D4, which was primarily designed t o test for D series mineralization, intersected 1.5 %
eU 3O8 over 4.6 metres indicating further expansion of the A series lenses in the up-dip direction. This result
builds on previous expansion drill results for that area, which include 1.7% eU 3O8 over 8.6 metres in drill
hole WR-582D3 (see Denison’s Press Release dated July 24, 2017).
Drill hole WR-682D1, which was completed approximat ely 25 metres down-dip of the current resources
estimated for the A series lenses, intersected 1.3% eU 3O8 over 3.6 metres. This result indicates further
expansion of the A series lenses in that area.
A, B, and C Series Infill and Delineation Nearing Completion
Infill and delineation drilling at Gryphon continue s, with the objective of bringing the inferred reso urces
estimated for the deposit to an indicated level of confidence. In total, 38 infill and delineation drill holes have
been completed with a further four holes remaining.
The results within the A and B series lenses contin ue to show good consistency with the current inferr ed
block model. Most notable is the result in drill h ole WR-572D1, which returned a mineralized interval of
1.3% eU 3O8 over 21.8 metres, including 3.9% eU 3O8 over 5.3 metres, which represents a significant
expansion of the mineralized extents of the A and B series lenses in the central portion of the deposi t,
indicating potential for resource growth in that area of the deposit.
Although drilling has confirmed the continuity of mineralization along the C series plane, the grades returned
from preliminary radiometric equivalent probe resul ts have been lower than what was expected when
compared to the current inferred block model. This possibly suggests a different structural control on the C
series lens mineralization and further infill drilling is expected to test this scenario.
Illustrative Figures
A plan map of the Gryphon A, B, C, D and E series l enses is provided in Figure 1. The inset on Figure 1
shows a schematic cross section of the A, B, C, D a nd E series lenses and their respective inclined
longitudinal section windows (as shaded rectangles) . Figures 2 to 6 provide inclined longitudinal sect ions
of the Gryphon A, B, C, D and E series lenses respectively.
The mineralized lenses which occur in the A series plane, immediately below the unconformity, and alon g
strike to the northeast of the Gryphon deposit have now been designated E series lenses and coloured
purple. The modelled mineralized lenses shown in F igures 1 to 6 are defined using a 0.05% U 3O8 grade
shell and minimum thickness of two metres and have been updated following receipt of the winter 2017
assay results. There is no certainty that the modelled mineralized lenses shown will constitute future mineral
resources and they may be subject to modifications as further drilling data becomes available.
Further details regarding the Gryphon deposit and t he current mineral resource estimates are provided in
the NI 43-101 Technical Report for the Wheeler Rive r project titled “Preliminary Economic Assessment for
the Wheeler River Uranium Project, Saskatchewan, Ca nada" dated April 8, 2016 with an effective date of
March 31, 2016. A copy of this report is availabl e on Denison’s website and under its profile on SEDAR
at www.sedar.com and on EDGAR at www.sec.gov/edgar.shtml.
Detailed Radiometric Equivalent Probe Results
The following tables provide the radiometric equiva lent probe results from the additional 17 drill hol es
completed during the summer 2017 exploration program at Wheeler River.
Table 1: Radiometric equivalent probe results for drill holes targeting the Gryphon D and E series lenses
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Section Drill Hole From
(m) To (m) Length
(m) 5
eU 3O8
(%) 1,2,4 Lens Designation 6
5175GP
WR-694 566.3 567.3 1.0 0.11 E Series
and 571.5 572.5 1.0 0.10 E Series
and 708.5 709.5 1.0 0.27 D Series
and 717.8 720.5 2.7 0.62 D Series
including 3 719.4 720.4 1.0 1.0 D Series
and 722.8 726.5 3.7 4.8 D Series
including 3 723.0 725.5 2.5 7.0 D Series
and 727.1 728.1 1.0 0.10 D Series
5200GP
WR-689D2 545.8 547.2 1.4 0.32 E Series
and 564.8 565.8 1.0 0.46 E Series
and 628.3 629.3 1.0 0.28 A Series
and 675.0 676.0 1.0 0.23 D Series
and 679.8 680.9 1.1 1.0 D Series
and 686.9 689.4 2.5 0.55 D Series
including 3 688.3 689.3 1.0 1.1 D Series
and 694.0 695.0 1.0 1.2 D Series
and 697.8 698.8 1.0 2.3 D Series
WR-689D3 538.5 540.8 2.3 0.44 E Series
and 547.4 552.1 4.7 5.0 E Series
including 3 548.9 551.6 2.7 8.5 E Series
and 565.4 566.4 1.0 0.20 D Series
5225GP
WR-690D1 617.8 619.2 1.4 0.17 A Series
and 695.2 697.2 2.0 0.48 D Series
and 717.9 719.9 2.0 1.5 D Series
including 3 717.9 718.9 1.0 2.8 D Series
and 724.0 725.0 1.0 6.4 D Series
WR-650D1 671.1 672.2 1.1 0.30 A Series
and 676.1 677.1 1.0 0.21 A Series
WR-690D2 565.5 567.0 1.5 0.88 E Series
including 3 565.9 566.9 1.0 1.2 E Series
and 664.7 665.7 1.0 0.20 D Series
and 668.5 669.5 1.0 0.11 D Series
and 686.4 687.4 1.0 0.53 D Series
and 694.4 695.4 1.0 0.10 D Series
and 700.9 701.9 1.0 0.57 D Series
and 711.0 714.7 3.7 3.8 D Series
including 3 711.2 714.5 3.3 4.2 D Series
and 717.9 721.4 3.5 0.36 D Series
WR-690D3 558.8 560.2 1.4 1.2 E Series
including 3 559.1 560.1 1.0 1.6 E Series
and 573.0 574.0 1.0 0.75 E Series
and 656.9 657.9 1.0 0.12 D Series
WR-654D1 723.9 725.8 1.9 0.70 D Series
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including 3 724.6 725.6 1.0 1.0 D Series
and 733.0 734.0 1.0 0.12 D Series
and 738.8 739.8 1.0 0.11 D Series
and 745.2 746.4 1.2 4.3 D Series
including 3 745.4 746.4 1.0 5.1 D Series
and 760.5 761.5 1.0 0.18 D Series
WR-638D4 710.6 715.2 4.6 1.5 A Series
including 3 712.4 715.0 2.6 2.5 A Series
and 771.5 774.3 2.8 0.69 D Series
including 3 772.4 773.4 1.0 1.3 D Series
and 776.5 777.5 1.0 0.46 D Series
and 786.1 787.9 1.8 3.3 D Series
including 3 786.7 787.8 1.1 5.1 D Series
5250GP
WR-657D1 567.1 568.6 1.5 0.22 E Series
and 587.0 588.0 1.0 0.12 E Series
and 708.2 713.4 5.2 2.0 D Series
including 3 708.6 711.7 3.1 3.1 D Series
Notes:
1. eU 3O8 is radiometric equivalent U3O8 from a calibrated total gamma downhole probe. eU 3O8 results are preliminary in nature
and all mineralized intervals will be sampled and submitted for chemical U3O8 assay.
2. Intersection interval is composited above a cut- off grade of 0.1% eU 3O8 unless otherwise indicated.
3. Intersection interval is composited above a cut- off grade of 1.0% eU 3O8.
4. Composites are compiled using 1.0 metre minimum ore thickness and 2.0 metres maximum waste
5. As the drill holes are oriented steeply toward t he northwest the true thickness of both the basemen t and inconformity
mineralization is expected to be approximately 75% of the intersection lengths (the basement mineralization is interpreted
to dip moderately to the southeast and the unconformity mineralization is interpreted to be flat-lying).
6. Drill holes targeting the D and E series lens mi neralization, in some cases, also intersect mineralization in the A and/or B
and/or C stratigraphic horizons outside of the Gryphon resource area.
Table 2: Radiometric equivalent probe results for Gryphon deposit A, B, C infill, delineation and expansion
drill holes
Section Drill Hole From
(m) To (m) Length
(m) 5
eU 3O8
(%) 1,2,4 Lens Densignation 6
4925GP
WR-572D2 649.6 655.8 6.2 0.41 A Series
including 3 654.5 655.5 1.0 1.3 A Series
and 690.3 691.3 1.0 0.55 B Series
and 703.8 706.4 2.6 0.25 C Series
4950GP
WR-682D1 728.7 729.7 1.0 0.14 A Series
and 758.6 759.6 1.0 0.12 A Series
and 761.6 765.2 3.6 1.3 A Series
including 3 763.0 764.4 1.4 2.8 A Series
4975GP
WR-572D1 631.3 632.3 1.0 0.15 A Series
and 638.2 639.2 1.0 0.10 A Series
and 639.5 661.3 21.8 1.3 A Series
including 3 650.7 651.9 1.2 2.5 A Series
including 3 654.9 660.2 5.3 3.9 A Series
and 682.8 691.4 8.6 0.48 B Series
and 687.6 688.6 1.0 1.7 B Series
and 690.2 691.2 1.0 1.2 B Series
6
5025GP
WR-564D2 720.5 721.5 1.0 0.37 A Series
and 730.7 732.4 1.7 0.38 A Series
and 735.5 739.4 3.9 1.8 A Series
including 3 737.0 739.0 2.0 3.2 A Series
and 757.7 758.7 1.0 0.22 B Series
WR-568D2 755.7 757.7 2.0 0.20 C Series
WR-564D3 707.1 708.1 1.0 0.18 A Series
and 713.4 714.4 1.0 0.14 A Series
and 716.3 721.7 5.4 5.8 A Series
including 3 717.9 720.7 2.8 11.0 A Series
and 741.4 746.8 5.4 0.61 B Series
including 3 741.7 742.7 1.0 1.04 B Series
including 3 745.4 746.4 1.0 1.36 B Series
and 749.7 750.7 1.0 0.16 B Series
and 757.9 763.1 5.2 0.30 C Series
and 767.3 768.3 1.0 0.36 C Series
and 770.4 771.4 1.0 1.5 C Series
5075GP
WR-568D1 728.1 734.2 6.1 0.17 A Series
and 739.9 743.9 4.0 0.16 B Series
Notes:
1. eU 3O8 is radiometric equivalent U3O8 from a calibrated total gamma downhole probe. eU 3O8 results are preliminary in nature
and all mineralized intervals will be sampled and submitted for chemical U3O8 assay.
2. Intersection interval is composited above a cut- off grade of 0.1% eU 3O8 unless otherwise indicated.
3. Intersection interval is composited above a cut- off grade of 1.0% eU 3O8.
4. Composites are compiled using 1.0 metre minimum ore thickness and 2.0 metres maximum waste
5. As the drill holes are oriented steeply toward t he northwest and the basement mineralization is interpreted to dip moderately
to the southeast, the true thickness of the mineralization is expected to be approximately 75% of the intersection lengths.
6. Drill holes targeting the A, B and C series lens mineralization, in some cases, also intersect mineralization in the D and/or
E stratigraphic horizons outside of the Gryphon resource area.
Qualified Persons and Data Quality
Dale Verran, MSc, P.Geo, Pr.Sci.Nat., Denison's Vice President, Exploration, who is a Qualified Person in
accordance with the requirements of NI 43-101 has r eviewed and approved the technical information
contained in this release. The Company currently re ports preliminary radiometric equivalent grades
("eU 3O8"), derived from a calibrated downhole total gamma probe, during its exploration programs and
subsequently reports definitive assay grades follow ing sampling and chemical analysis of the mineraliz ed
drill core. Radiometric equivalent probe results ar e subject to verification procedures by qualified p ersons
employed by Denison prior to disclosure. For furthe r details on the total gamma downhole probe methods
employed by Denison, QAQC procedures and data verif ication procedures please see Denison's Annual
Information Form dated March 23, 2017 filed under the Company's profile on SEDAR (www.sedar.com).
About Wheeler River
Wheeler River is the largest undeveloped high-grade uranium project in the infrastructure rich eastern
portion of the Athabasca Basin region, in northern Saskatchewan. The project is a joint venture betwe en
Denison (60% and operator), Cameco Corp. (“Cameco”) (30%), and JCU (Canada) Exploration Company
Limited (“JCU”) (10%), and is host to the high-grade Gryphon and Phoenix uranium deposits discovered by
Denison in 2014 and 2008, respectively. The Gryphon deposit is hosted in basement rock and is currentl y
estimated to contain inferred resources of 43.0 mil lion pounds U 3O8 (above a cut-off grade of 0.2% U 3O8)
based on 834,000 tonnes of mineralization at an ave rage grade of 2.3% U 3O8. The Phoenix unconformity
deposit is located approximately 3 kilometres to th e southeast of Gryphon and is estimated to include
indicated resources of 70.2 million pounds U 3O8 (above a cut-off grade of 0.8% U 3O8) based on 166,000
7
tonnes of mineralization at an average grade of 19.1% U 3O8, and is the highest grade undeveloped known
uranium deposit in the world.
On April 4th, 2016, Denison announced the results of a Preliminary Economic Assessment (“PEA”) for the
Wheeler River Project, which considers the potentia l economic merit of co-developing the high-grade
Gryphon and Phoenix deposits as a single undergroun d mining operation. The PEA returned a base case
pre-tax Internal Rate of Return ("IRR") of 20.4% ba sed on the current long term contract price of uran ium
(US$44.00 per pound U 3O8), and Denison's share of estimated initial capital expenditures ("CAPEX") of
CAD$336M (CAD$560M on 100% ownership basis). Explo ration results from the subsequent drilling
programs have not been incorporated into the resour ce estimate or the PEA. The PEA is preliminary in
nature and includes inferred mineral resources that are considered too speculative geologically to have the
economic considerations applied to them to be categ orized as mineral reserves, and there is no certain ty
that the preliminary economic assessment will be realized. Mineral resources are not mineral reserves and
do not have demonstrated economic viability. On Jul y 19th, 2016 Denison announced the initiation of a
Pre-Feasibility Study ("PFS") for the Wheeler River property and the complimentary commencement of an
infill drilling program at the Gryphon deposit to b ring the inferred resources to an indicated level o f
confidence.
As previously announced on January 10, 2017, Deniso n has entered into an agreement with its Wheeler
River Joint Venture partners, Cameco and JCU, to fu nd 75% of Joint Venture expenses in 2017 and 2018
(ordinarily 60%) in exchange for an increase in Denison's interest in the project to up to approximately 66%.
Under the terms of the agreement, Cameco will fund 50% of its ordinary 30% share in 2017 and 2018, and
JCU is expected to continue to fund its 10% interest in the project.
About Denison
Denison is a uranium exploration and development company with interests focused in the Athabasca Basin
region of northern Saskatchewan, Canada. In addition to its 60% owned Wheeler River project, which hosts
the high-grade Phoenix and Gryphon uranium deposits , Denison's exploration portfolio consists of
numerous projects covering approximately 359,000 he ctares in the Athabasca Basin region, including
340,000 hectares in the infrastructure rich eastern portion of the Athabasca Basin. Denison's interest s in
Saskatchewan also include a 22.5% ownership interest in the McClean Lake joint venture (“MLJV”), which
includes several uranium deposits and the McClean L ake uranium mill, which is currently processing ore
from the Cigar Lake mine under a toll milling agreement, plus a 25.17% interest in the Midwest deposit and
a 63.63% interest in the J Zone deposit on the Wate rbury Lake property. Both the Midwest and J Zone
deposits are located within 20 kilometres of the McClean Lake mill.
Denison is also engaged in mine decommissioning and environmental services through its Denison
Environmental Services division and is the manager of Uranium Participation Corp., a publicly traded
company which invests in uranium oxide and uranium hexafluoride.
For more information, please contact
David Cates (416) 979-1991 ext. 362
President and Chief Executive Officer
Sophia Shane (604) 689-7842
Investor Relations
Follow Denison on Twitter @DenisonMinesCo
Cautionary Statement Regarding Forward-Looking Statements
Certain information contained in this press release constitutes "forward-looking information", within the meaning of the United States
Private Securities Litigation Reform Act of 1995 an d similar Canadian legislation concerning the busin ess, operations and financial
performance and condition of Denison.
Generally, these forward-looking statements can be identified by the use of forward-looking terminolog y such as "plans", "expects",
"budget", "scheduled", "estimates", "forecasts", "intends", "anticipates", or "believes", or the negatives and/or variations of such words and
phrases, or state that certain actions, events or results "may", "could", "would", "might" or "will be taken", "occur", "be achieved" or "has
the potential to". In particular, this press release contains forward-looking information pertaining to the following: exploration (including
drilling) and evaluation activities, plans and objectives; potential mineralization of drill targets; the estimates of Denison's mineral resources
8
and the results of its PEA; and Denison’s percentage in its properties and its plans and agreements with its joint venture partners, as
applicable; and Denison’s percentage in its properties and its plans and agreements with its joint ven ture partners, as applicable.
Statements relating to "mineral reserves" or "mineral resources" are deemed to be forward-looking information, as they involve the implied
assessment, based on certain estimates and assumptions that the mineral reserves and mineral resources described can be profitably
produced in the future.
Forward looking statements are based on the opinions and estimates of management as of the date such statements are made, and they
are subject to known and unknown risks, uncertainties and other factors that may cause the actual results, level of activity, performance
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that the expectations reflected in this forward-looking information are reasonable but no assurance can be given that these expectations
will prove to be accurate and may differ materially from those anticipated in this forward looking information. For a discussion in respect
of risks and other factors that could influence forward-looking events, please refer to the factors discussed in Denison's Annual Information
Form dated March 23, 2017 under the heading "Risk Factors". These factors are not, and should not be construed as being exhaustive.
Accordingly, readers should not place undue reliance on forward-looking statements.
The forward-looking information contained in this press release is expressly qualified by this cautionary statement. Any forward-looking
information and the assumptions made with respect thereto speaks only as of the date of this press release. Denison does not undertake
any obligation to publicly update or revise any forward-looking information after the date of this press release to conform such information
to actual results or to changes in Denison's expectations except as otherwise required by applicable legislation .
Cautionary Note to United States Investors Concerning Estimates of Measured, Indicated and Inferred Mineral Resources: This
press release may use the terms “measured”, “indicated” and “inferred” mineral resources. United States investors are advised that while
such terms are recognized and required by Canadian regulations, the United States Securities and Exchange Commission does not
recognize them. “Inferred mineral resources” have a great amount of uncertainty as to their existence, and as to their economic and legal
feasibility. It cannot be assumed that all or any part of an inferred mineral resource will ever be upgraded to a higher category. Under
Canadian rules, estimates of inferred mineral resources may not form the basis of feasibility or other economic studies. United States
investors are cautioned not to assume that all or any part of measured or indicated mineral resources will ever be converted into mineral
reserves. United States investors are also cautioned not to assume that all or any part of an inferred mineral resource exists, or is
economically or legally mineable.