Denison Announces Significant Increase to Summer 2017 Drilling Program at Wheeler River
Denison Mines Corp.
1100 – 40 University Ave
Toronto, ON M5J 1T1
www.denisonmines.com
@DenisonMinesCo
PRESS RELEASE
DENISON ANNOUNCES SIGNIFICANT INCREASE TO
SUMMER 2017 DRILLING PROGRAM AT WHEELER RIVER
Toronto, ON – September 12, 2017 Denison Mines Corp. (“Denison” or the “Company”) (T SX: 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 n ow expected to continue into October and will be
increased by approximately 16 drill holes (6,500 me tres). 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).
The summer 2017 drilling program has focused on the infill and expansion of the Gryphon deposit, and has
already resulted in the successful expansion of the A, B and D series of mineralized lenses, as well a s the
recognition and expansion of the new E series lense s (see Denison’s Press Releases dated July 24 and
August 30, 2017). Most notably, the D and E series lenses are not included in the current resources
estimated for the Gryphon deposit, and the expansio ns of the A and B series lenses also occur outside of
the current resources.
The additional drill holes planned for the remainde r of the summer 2017 drilling program are designed to
continue the successful expansion of high-grade min eralization in priority target areas – with potenti al to
convert drill results into resources. As a result, the drilling is expected to be completed on a spaci ng with
the potential to add indicated or inferred resources to the Gryphon deposit ahead of the resource estimate
scheduled for later in the year, and the Pre-Feasibility Study (“PFS”) scheduled for 2018.
David Cates, Denison’s President and CEO, commented, “The exploration team set out this year with a
focus on increasing the confidence in our resources at Gryphon, ahead of the PFS planned for 2018. In
addition to successful infill results, throughout t he winter and summer drilling programs, we’ve had
significant success in our efforts to expand the ex tent of the mineralization at and in the vicinity o f the
Gryphon deposit – particularly in the D series and new E series of lenses. With our drilling operatio ns
on track and positive results continuing to come in from the field, we see this as a unique opportunity to
extend the 2017 summer program and continue drillin g into October. We’re doing this in an attempt to
maximize the number of new pounds that can be inclu ded in an updated resource estimate for the
Wheeler River project, and ultimately the PFS.”
In connection with the extended drilling program, t he Wheeler River Joint Venture (“WRJV”) approved an
increased budget for 2017, including approximately CAD$2,300,000 in additional spending through to the
end of 2017 (“Additional Budget”). Denison will fu nd 100% of the Additional Budget on the behalf of t he
WRJV in 2017, and the costs will become Joint Ventu re Expenses on or after January 1, 2018 – at which
point all WRJV partners will be responsible to fund their shares in accordance with the terms of the W RJV
and the special agreement amongst the joint venture partners, dated January 9, 2017 (see Denison’s Press
Release dated January 10, 2017). The January 9, 201 7 special agreement allows for Denison to increase
its ownership in the Wheeler River project from 60% to approximately 66% by funding 75% of joint venture
expenses in 2017 and 2018. 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.
Deferral of the Hook-Carter 2017 Drilling Program
Denison has elected to defer the Hook-Carter drilli ng program planned for the late summer of 2017 to t he
winter of 2018. Higher costs associated with helico pter-supported drilling programs in summer months,
complications with recent forest fires in the area, and the integration and interpretation of signific ant
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amounts of ground geophysical data acquired earlier this year, have all been contributing factors to t he
decision. The drilling program originally planned f or the summer of 2017 included a reconnaissance fiv e-
hole drill program of approximately 2,700 metres. Ground geophysical surveys, including ground resistivity
and electromagnetic surveying, have been completed as per plan.
Dale Verran, Denison’s Vice President of Exploratio n, commented, “Our team is extremely eager to
commence our first drilling campaign at Hook-Carter ; however, we have decided to defer the program
until winter 2018 in response to numerous factors. A winter 2018 drilling program is expected to have
lower costs per metre and thus should allow for inc reased target testing for budget spent. A deferral
also provides us with additional time for optimized target selection through the continued integration
and interpretation of the ground geophysical data collected earlier this year.”
The Hook-Carter project is owned 80% by Denison and 20% by ALX Uranium Corp. (“ALX”), and Denison
has agreed to fund ALX's share of the first CAD$12M in expenditures (see Denison’s Press Releases dated
October 13th and November 7th, 2016). The Hook-Cart er project consists of 38 claims, totaling nearly
20,000 hectares, and is located near the southweste rn margin of the Athabasca Basin. The project is
highlighted by 15 kilometres of strike potential al ong the prolific Patterson Lake Corridor – host to the
recently discovered Triple R deposit (Fission Urani um Corp.), Arrow deposit (NexGen Energy Ltd.), and
Spitfire discovery (Purepoint Uranium Group Inc., C ameco Corp., and AREVA Resources Canada Inc.),
which occur within 8 to 20 kilometres of the property. The property is significantly underexplored compared
to other properties along this trend, with only five of eight historic drill holes located along the 15 kilometres
of Patterson Lake Corridor strike length. The prope rty also covers significant portions of the Derkson and
Carter Corridors which provide additional priority target areas.
Qualified Persons and Further Details
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.
Further details regarding the Gryphon deposit and the Wheeler River project are provided in the NI 43-101
Technical Report for the Wheeler River project titl ed "Preliminary Economic Assessment for the Wheeler
River Uranium Project, Saskatchewan, Canada" dated April 8, 2016 with an effective date of March 31,
2016. A copy of this report is available on Deniso n's website and under its profile on SEDAR at
www.sedar.com and on EDGAR at www.sec.gov/edgar.shtml. Figure 1 provides the location and basement
geology of the Wheeler River project. Further deta ils on Denison’s pipeline exploration projects are
available in the Company’s MD&A available on Deniso n's website and under its profile on SEDAR at
www.sedar.com and on EDGAR at www.sec.gov/edgar.shtml.
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
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
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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.
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 64.22% 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
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. 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
or achievements of Denison to be materially different from those expressed or implied by forward-looking statements. Denison believes
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 .
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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.
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Figure 1: Location map and basement geology of the Wheeler River project.