Denison Reports Expansion of the Huskie Zone with Intersection of 4.5% U3O8 over 6.0 Metres
Denison Mines Corp.
1100 – 40 University Ave
Toronto, ON M5J 1T1
www.denisonmines.com
@DenisonMinesCo
PRESS RELEASE
DENISON REPORTS EXPANSION OF THE HUSKIE ZONE WITH
INTERSECTION OF 4.5% U3O8 OVER 6.0 METRES
Toronto, ON – April 25, 2018 Denison Mines Corp. (“Denison” or the “Company”) (DML: TSX, DNN: NYSE
American) is pleased to report the expansion of the Huskie zone with the receipt of chemical assay (“U3O8”)
results from the Company’s winter 2018 diamond drilling program on the 64.22% owned Waterbury Lake
project. The winter drilling program involved 9,794 metres of diamond drilling in 19 drill holes, and was
focused on 50 metre step-out drilling along strike and down-dip of the Huskie zone, as well as wider-spaced
reconnaissance drilling to the west along the geological trend. The winter drilling program is part of a larger
14,400 metre drill program planned for Waterbury Lake in 2018, with the remainder to be completed during
the summer months.
Winter 2018 Drilling Program Highlights:
The basement-hosted uranium mineralization discovered by Denison in 2017 (see Denison’s press release
dated October 11, 2017) was extended down-dip as a result of step-out drilling completed on an
approximate 50 metre spacing. The results were highlighted by the following intercepts:
• 4.5% U 3O8 over 6.0 metres, including 5.8% U 3O8 over 4.5 metres in drill hole WAT18-452,
located approximately 100 metres down-dip of drill hole WAT17-446A, which returned 9.1% U 3O8
over 3.7 metres (including 16.8% U 3O8 over 2.0 metres) in the summer of 2017;
• 0.57% U 3O8 over 6.3 metres, including 1.9% U 3O8 over 1.0 metre also in drill hole WAT18-452;
• 0.62% U 3O8 over 1.0 metre in drill hole WAT18-460A, located approximately 50 metres along strike
to the west of drill hole WAT17-450A, which returne d 1.5% U 3O8 over 4.5 metres (including 3.9%
U3O8 over 1.0 metres) in the summer of 2017.
Dale Verran, Denison’s Vice President of Exploration, commented, “Drill hole WAT18-452 represents the
second-best hole to date at Huskie in terms of comb ined grade and thickness and a meaningful
expansion in the down-dip direction. The high-grade mineralization at Huskie appears to be
controlled by the intersection of east-west striking faults, associated with the graphitic gneiss unit,
and cross-cutting northeast striking faults, possibly related to the regional Midwest structure. This
has led to high-grade ‘lens stacking’ in a northeast direction as opposed to the lenses being laterally
extensive along strike to the east and west. Our te am will utilize this improved understanding to
target additional high-grade mineralization proxima l to Huskie and along this northeast structural
trend.”
The regional Midwest structure hosts the Midwest A and Midwest Main deposits (25.17% Denison), which
are located approximately three and six kilometres to the southwest of the Huskie zone, respectively, and
is interpreted to control the location of the J Zon e deposit on the Waterbury Lake property, as well a s the
Roughrider deposit, which are located 1.5 kilometres to the southwest of the Huskie zone.
Further details of the results from the winter 2018 drilling program are provided below, including composited
chemical assay results in Table 1. The location of the Waterbury Lake project and the location of the winter
2018 drill holes are provided in Figures 1 to 3.
2
Details of Winter 2018 Drilling Results
A total of 19 drill holes were completed as part of the winter 2018 Waterbury Lake exploration program:
• Fourteen drill holes were completed around the Hus kie zone as 50 metre step-outs from the
mineralization identified in 2017 (see Denison’s press release dated October 11, 2017). Drill holes
were completed along strike to the east (two drill holes), along strike to the west (seven drill holes)
and in the down-dip direction (five drill holes) of the Huskie mineralization. All drilling was designed
to test the basement units below the sub-Athabasca unconformity.
• An additional five reconnaissance drill holes were completed along two drill fences west of the
Huskie zone at 150 metres (three drill holes) and 450 metres (two drill holes), respectively.
Uranium mineralization was intersected in five dril l holes during the winter 2018 program, as describe d
below and provided in Table 1:
• Down-dip of Huskie, drill hole WAT18-452 extended mineralization by approximately 50 metres ,
intersecting four stacked lenses of mineralization which are interpreted to occur along, or proximal
to, the northeast structural trend interpreted to b e associated with the regional Midwest structure.
Results included 4.5% U 3O8 over 6.0 meters (including 5.8% U 3O8 over 4.5 meters), and 0.57%
U3O8 over 6.3 meters (including 1.9% U 3O8 over 1.0 meter).
• At the western extent of Huskie, drill hole WAT18-460A was designed to test approximately 50
metres along strike to the west of drill hole WAT17 -450A (1.5% U 3O8 over 4.5 metres), and
intersected 0.62% U 3O8 over 1.0 metre.
• Drill hole WAT18-464A returned a mineralized inter val of 0.05% U 3O8 over 1.0 metre. While this
result also extended the mineralized zone further t o the west, located 50 metres up-plunge to the
west of WAT18-460A, the results indicate a weakening of the mineralization to the west.
• At the eastern extent of Huskie, drill hole WAT18-462 intersected weak mineralization (0.03% U 3O8
over 1.5 metres) approximately 50 metres along stri ke to the east of drill hole WAT17-443 (1.2%
U3O8 over 1.0 metres).
• Drill hole WAT18-468 tested a resistivity anomaly, identified from a 20 08 geophysical survey,
located 450 metres to the west along strike of the Huskie Zone and intersected weak mineralization
(0.03% U 3O8 over 2.0 metres) approximately 300 metres below the unconformity. The mineralized
intercept was not associated with any significant alteration or structure.
Table 1. Assay results for the Waterbury Lake winter 2018 drill program.
Drill Hole From (m) To (m) Length (m) 6 U 3O8 (%) 1,2,5
WAT18-452 405.5 409.5 4.0 0.18
and 416.0 417.0 1.0 0.10
and 419.5 425.5 6.0 4.5
Including 3 419.5 424.0 4.5 5.8
and 435.7 442.0 6.3 0.57
Including 3 438.0 439.0 1.0 1.9
WAT18-460A 303.0 304.0 1.0 0.62
WAT18-462 4 245.6 247.1 1.5 0.03
WAT18-464A 248.0 249.0 1.0 0.05
WAT18-468 4 500.7 502.7 2.0 0.03
Notes:
1. U 3O8 is the chemical assay of mineralized split core samples.
2. Intersection interval is composited above a cut- off grade of 0.05% U 3O8 unless otherwise indicated.
3. Intersection interval is composited above a cut- off grade of 1.0% U 3O8.
4. Intersection interval is composited above a cut- off grade of 0.01% U 3O8.
5. Composites are compiled using 1.0 metre minimum ore thickness and 2.0 metres maximum waste.
6. As the drill holes are oriented steeply toward t he south-southeast and the mineralized lenses are i nterpreted to dip
moderately to the north, the true thickness of mineralization is expected to be approximately 75% of the intersection lengths.
3
The remaining drill holes at Huskie successfully tested their designated targets, and while variable structure
and alteration was encountered, no additional mineralization was intersected.
Geology of the Huskie Zone
To date, drilling has been completed on an approxim ate 50 x 50 metre grid pattern which has allowed fo r
the wide-spaced definition of a zone of entirely ba sement-hosted mineralization with geological featur es
consistent with basement-hosted deposits in the Athabasca Basin. The mineralized zone is hosted primarily
within a faulted graphite-bearing pelitic gneiss (“graphitic gneiss”), which forms part of an east-west striking,
northerly dipping package of metasedimentary rocks flanked to the north and south by granitic gneisses .
The Athabasca Group sandstones that unconformably o verly the basement rocks are approximately 210
metres thick.
Interpretation indicates the mineralization occurs as parallel, stacked lenses, which are conformable to the
foliation and fault planes within the graphitic gneiss. The location of the mineralized lenses and their strike
extent in the east-west direction appears to be con trolled by cross-cutting, northeast striking faults . These
faults are interpreted to be part of the regional M idwest structure and indicate the potential for add itional
high-grade basement-hosted mineralization in a northeast orientation.
The high-grade mineralization is comprised of massi ve to semi-massive uraninite (pitchblende) and
subordinate bright yellow secondary uranium mineral s occurring along fault or fracture planes, or as
replacement along foliation planes. Disseminations of lower grade mineralization occur within highly altered
rocks proximal to fault planes. The mineralization is intimately associated with hematite, which both occur
central to a broad and pervasive alteration envelope of white clays, chlorite and silicification.
The mineralized zone defined to date occurs between 50 and 225 metres vertically below the sub-
Athabasca unconformity (265 and 435 metres vertical ly below surface) and measures approximately 250
metres along strike, up to 170 metres along dip, with individual lenses varying in interpreted true thickness
between approximately 2 and 7 metres.
Waterbury Lake Property
The Waterbury Lake property consists of multiple cl aims covering 40,256 hectares, and is located in th e
infrastructure rich eastern portion of the Athabasc a Basin region in northern Saskatchewan. The prope rty
is jointly owned by Denison (64.22%) and Korea Wate rbury Uranium Limited Partnership (“KWULP”)
(35.78%) through the Waterbury Lake Uranium Limited Partnership (“WLULP”). KWULP consists of a
consortium of investors in which Korea Hydro & Nuclear Power (“KHNP”) holds a majority position. KWULP
has elected not to fund the 2018 exploration progra m and, as a result, will incur dilution of its owne rship
interest in the WLULP. KHNP is also a significant shareholder in Denison, holding 58,284,000 common
shares of Denison, which represents approximately 1 0.42% of the Company’s issued and outstanding
common shares.
Illustrative Figures
Location of the winter 2018 drill collars on Deniso n’s Waterbury Lake project, relative to the J Zone and
Roughrider deposits, are shown in Figure 1. Figure 2 provides the simplified basement geology map of the
Huskie zone at the sub-Athabasca unconformity showi ng the location of the winter 2018 drill holes. An
inclined longitudinal section showing the location of mineralized pierce points and the interpreted
mineralized wireframes is presented in Figure 3. The mineralized lenses shown are defined using a 0.05%
U3O8 over 1.0 metre cut-off and modelled using a minimu m thickness of two metres. 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.
Sampling and Assay Procedures
Drill core with anomalous total gamma radioactivity (>500 counts per second using a RS-120 or RS-125
scintillometer) was sampled over 0.5 metre interval s. Sampling is undertaken on site by splitting the core
in half, with one half submitted for analysis and t he other half retained in the core box for future r eference.
4
Uranium chemical assays are performed by the Saskat chewan Research Council (“SRC”) Geoanalytical
Laboratories located in Saskatoon. Sample preparati on involves crushing and pulverizing core samples t o
90% passing -106 microns. Splits of the resultant p ulps are initially submitted for multi-element ICP- MS
analysis following partial (HNO 3:HCl) and total (HF:HNO 3:HClO 4) digestions. Samples with ≥ 1,000 ppm U
(partial digest) are re-assayed for U 3O8 using an ISO/IEC 17025:2005 accredited method for the
determination of U 3O8 weight %. Pulp splits are digested using aqua-regi a and the solution analyzed for
U3O8 weight % using ICP-OES. Core recovery at the Huski e zone is typically 100% and therefore
radiometric equivalent U3O8 grades ("eU 3O8") are not required as a substitute for chemical U3O8 assays. In
addition to internal checks by SRC Geoanalytical La boratories, the Company has rigorous quality
assurance and quality control ("QAQC") procedures including the insertion of standard reference materials,
blanks and field duplicates. The assay data is subj ect to verification procedures by qualified persons
employed by Denison prior to disclosure. For furthe r details on the assay, QAQC and data verification
procedures please see Denison's Annual Information Form dated March 27, 2018 filed under the
Company's profile on SEDAR (www.sedar.com).
Qualified Persons
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.
About Denison
Denison is a uranium exploration and development company with interests focused in the Athabasca Basin
region of northern Saskatchewan, Canada. In additio n to its 63.3% owned Wheeler River project, which
ranks as the largest undeveloped high-grade uranium project in the infrastructure rich eastern portion of
the Athabasca Basin region, Denison's Athabasca Basin exploration portfolio consists of numerous projects
covering approximately 353,000 hectares. Denison's interests in Athabasca Basin also include a 22.5%
ownership interest in the McClean Lake joint ventur e (“MLJV”), which includes several uranium deposits
and the McClean Lake uranium mill, which is current ly processing ore from the Cigar Lake mine under a
toll milling agreement, plus a 25.17% interest in the Midwest and Midwest A deposits, and a 64.22% interest
in the J Zone deposit and Huskie discovery on the W aterbury Lake property. Each of Midwest, Midwest A,
J Zone and Huskie 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 interpretations, activities, plans and objectives, 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
5
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 27, 2018 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 .
This document contains certain information derived from third-party publications and reports, includin g estimates of resources and
mineralization of the Roughrider deposit, which Denison believes are reliable but have not been independently verified by Denison.
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.
6
Figure 1: Location of summer 2017 drill collars on Denison’s Waterbury Lake project.
7
Figure 2: Simplified basement geology map of the Huskie zone at the sub-Athabasca unconformity.
8
Figure 3: Inclined longitudinal section of the Huskie zone (looking south).