Denison Announces Further Extension of High-Grade “Huskie” Zone at Waterbury Lake with Final Summer Drill Holes
Denison Mines Corp.
1100 – 40 University Ave
Toronto, ON M5J 1T1
www.denisonmines.com
@DenisonMinesCo
PRESS RELEASE
DENISON ANNOUNCES FURTHER EXTENSION OF HIGH-GRADE
“HUSKIE” ZONE AT WATERBURY LAKE WITH FINAL
SUMMER DRILL HOLES
Toronto, ON – September 19, 2017 Denison Mines Corp. (“Denison” or the “Company”) (DML: TSX, DNN:
NYSE MKT) is pleased to report the completion of th e summer exploration drilling program at Waterbury
Lake, with the final five drill holes returning mul tiple additional high-grade intersections. The hig h-grade
and basement-hosted uranium mineralized zone has now been expanded to the extent of the current drilling
– measuring approximately 100 metres in strike length. The results from the final drill holes of the s ummer
program were highlighted by 1.0% eU 3O8 over 7.6 metres (including 4.6% eU 3O8 over 1.4 metres) in drill
hole WAT17-449, and 0.8% eU 3O8 over 7.9 metres (including 3.3% eU 3O8 over 1.0 metre and 1.3% eU 3O8
over 1.0 metre) in drill hole WAT17-450A.
The summer 2017 drill program at Waterbury Lake commenced in late July and has been highly successful
returning several high-grade uranium intersections from a target area located approximately 1.5 kilometres
to the northeast of the property’s J Zone uranium deposit. Following the discovery of uranium mineralization
in the first four drill holes of the program, the s cope of the program was increased in late August to allow
for a total of 9 drill holes, all of which have now been completed. Taken together, the summer progra m
included a total of 3,722 metres drilled and result ed in the wide-spaced definition (approximately 50 x 50
metre drill hole spacing) of a significant zone of entirely basement-hosted mineralization with geolog ical
features consistent with basement-hosted deposits in the Athabasca Basin. The new zone of mineralization
has been named the “Huskie” zone.
Today’s news is highlighted by the following:
• Drill hole WAT17-449 (1.0% eU 3O8 over 7.6 metres) and drill hole WAT17-450A (0.8% eU 3O8 over
7.9 metres) were located approximately 50 metres to the west of drill hole WAT17-446A (3.7%
eU 3O8 over 3.9 metres, see news release dated August 22, 2017), and have resulted in the
extension of the high-grade, basement-hosted minera lized zone to a total strike length of
approximately 100 metres;
• Drill results to date have defined a significant z one of basement-hosted mineralization, which
remains open in all directions, and has been named the “Huskie” zone;
• The notable increase in the size and intensity of the alteration envelope together with the thickening
of the faulted, graphitic gneiss along the westernmost fence of holes suggest exploration potential
is increasing to the west of discovery drill hole WAT17-443 (1.1% eU 3O8 over 0.8 metres, see news
release dated August 1, 2017).
Results are reported herein as preliminary radiomet ric equivalent grades ("eU 3O8") derived from a
calibrated downhole total gamma probe. The Company subsequently reports definitive assay grades
following sampling and chemical analysis of the mineralized drill core.
David Cates, Denison’s President and CEO, commented , “The Huskie zone is an exciting addition to
Denison’s eastern Athabasca Basin focused exploration and project development portfolio. Huskie
is located in close proximity to regional infrastructure and other strategic Denison assets, including
the McClean Lake mill and deposits (22.5% Denison), J Zone deposit (64.22% Denison) and the
Midwest deposits (25.17% Denison). This discovery, together with continued exploration success
on the Company’s flagship Wheeler River project, sp eaks to the skill and commitment of our
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Saskatoon based exploration team, and delivers on o ur strategy of focussing our exploration
spending on a select group of high-priority projects with potential for high-impact results.”
Dale Verran, Denison’s Vice President of Exploration, commented, “Our team is extremely encouraged
by the results of the summer program at Waterbury a nd how we have built upon the initial high-
grade intercept in discovery hole WAT17-443. The ba sement plumbing system appears to be
improving as we move west – as indicated by the increased number of mineralized lenses, a broader
and stronger alteration halo and a widening of the structured, graphitic package. An unconformity
offset and associated sandstone alteration has also caught our attention and provides a further
target for unconformity mineralization. The trend i s wide-open to the west and land-based for over
one kilometre. We look forward to reporting assay results over the coming weeks and planning the
2018 drill program.”
The Huskie Zone
Nine drill holes, completed on an approximate 50 x 50 metre spacing, have allowed for the wide-spaced
definition of a zone of entirely basement-hosted mi neralization with geological features consistent wi th
basement-hosted deposits in the Athabasca Basin. Th e mineralized zone is hosted primarily within a
faulted, graphite-bearing pelitic gneiss (“graphiti c gneiss”) which forms part of an east-west strikin g,
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. A major reverse fault, occurring alon g the upper contact of the graphitic gneiss, has re sulted
in approximately 15 metres of offset of the sub-Athabasca unconformity. Preliminary interpretation indicates
the mineralization occurs as parallel, stacked lenses which are conformable to the foliation and fault planes
within the graphitic gneiss. The high-grade mineral ization is comprised of massive to semi-massive
uraninite (pitchblende) and subordinate bright yell ow secondary uranium minerals occurring along fault or
fracture planes, or as replacement along foliation planes. Disseminations of lower grade mineralizatio n
occur within highly altered rocks proximal to fault planes. The mineralization is intimately associate d with
hematite, which both occur central to a broad and pervasive alteration envelope of white clays, chlorite and
silicification.
Of the eight drill holes designed to test for basem ent-hosted mineralization, seven holes intersected
significant mineralization – including high-grade i ntersections in four of the holes. A single hole wa s
designed to test for unconformity mineralization an d encountered bleaching, silicification, clay alter ation
and weak radioactivity in the lower sandstone, prox imal to a 15 metre unconformity offset which sugges ts
additional potential at the unconformity.
The mineralized zone defined to date occurs between 50 and 175 metres vertically below the sub-
Athabasca unconformity (265 and 390 metres vertical ly below surface) and measures approximately 100
metres along strike (current extent of drilling), u p to 120 metres along dip, with individual lenses v arying in
interpreted true thickness between approximately 2 and 7 metres. The zone is wide-open in all directio ns
in terms of the mineralization and associated alteration intersected.
A location map of the Huskie zone is provided in Fi gure 1. A simplified basement geology map,
representative cross-section, and inclined longitud inal section of the Huskie zone are provided in Fig ures
2, 3 and 4 respectively. Preliminary radiometric eq uivalent grades for the summer 2017 drill program a re
provided in Table 1. The radiometric equivalent gra des are provided as composites using a minimum
thickness of 1 metre and a minimum cut-off of 0.05% eU 3O8.
Table 1. Preliminary radiometric equivalent grades for the Waterbury Lake summer 2017 drill program.
Drill Hole From (m) To (m) Length (m) 5 eU 3O8 (%) 1,2,4
WAT17-443 280.5 293.1 12.6 0.13
and 6 296.8 298.0 1.2 0.77
WAT17-444 339.8 340.8 1.0 0.08
and 345.8 346.8 1.0 0.44
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and 360.6 361.6 1.0 0.14
WAT17-445 277.0 278.0 1.0 0.13
WAT17-446A 305.7 309.6 3.9 3.7
including 3 307.0 308.8 1.8 7.8
and 334.9 335.9 1.0 0.24
and 341.2 342.8 1.6 0.07
WAT17-447 No significant mineralization
WAT17-448 No significant mineralization
WAT17-449 321.9 323.2 1.3 0.10
and 344.9 345.9 1.0 0.25
and 349.2 350.2 1.0 0.06
and 369.2 376.8 7.6 1.0
including 3 375.0 376.4 1.4 4.6
and 379.4 384.5 5.1 0.21
WAT17-450A 279.7 282.6 2.9 0.08
and 315.1 323.0 7.9 0.77
including 3 319.2 320.2 1.0 3.3
including 3 321.4 322.4 1.0 1.3
and 335.2 336.4 1.2 0.11
WAT17-451 390.4 391.9 1.5 0.15
and 399.4 403.1 3.7 0.27
and 405.6 406.6 1.0 0.09
and 418.1 419.1 1.0 0.07
Notes:
1. eU 3O8 is radiometric equivalent U3O8 derived 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 0.05% 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 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.
6. This interval includes 1.1% eU 3O8 over 0.8 metres as reported previously.
Exploration Potential
The increase in the number of mineralized lenses together with the notable increase in the size and intensity
of the alteration envelope and the thickening of th e faulted graphitic gneiss, along the westernmost f ence
of holes, suggest exploration potential is increasi ng to the west of discovery drill hole WAT17-443.
Accordingly, several priority target areas have bee n identified which warrant follow-up in future dril ling
programs, summarized as follows:
• Along strike to the west: The final three drill holes of the summer 2017 prog ram (WAT17-449, WAT17-
450A and WAT17-451), along the westernmost drill fe nce, all intersected significant mineralization,
which is wide-open along strike to the west.
• Up-dip and down-dip: Along the westernmost drill fence, mineralization remains open up-dip of WAT17-
450A (0.8% eU 3O8 over 7.9 metres) and down-dip of WAT17-451 (0.3% e U 3O8 over 3.7 metres).
Furthermore, the 25 metre interval of strong clay a lteration and bleaching intersected in WAT17-448,
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approximately 57 metres down-dip of WAT17-446A (3.7% eU 3O8 over 3.9 metres, including 7.8% eU 3O8
over 1.8 metres), indicates the mineralizing system remains open at depth in this area.
• At the unconformity: Drill hole WAT17-447 which was designed to test th e unconformity above the
faulted graphitic gneiss encountered bleaching, silicification, clay alteration and weak radioactivity in the
lower sandstone proximal to the interpreted 15 metr e unconformity offset. These features suggest
potential for unconformity-hosted deposits along strike.
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 2017 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.
The J Zone deposit, located on the Waterbury Lake p roperty, occurs at the sub-Athabasca unconformity
and is estimated to contain indicated resources of 12.8 million pounds U 3O8 based on 291,000 tonnes of
mineralization an average grade of 2.0% U 3O8. The Roughrider deposit on Rio Tinto’s Roughrider property
is located immediately along strike to the east of J Zone deposit and occurs at the sub-Athabasca
unconformity and below within the basement rocks. Prior to acquisition by Rio Tinto in 2012, the Roughrider
deposit was estimated to contain indicated resources of 17.2 million pounds U 3O8 based on 394,200 tonnes
of mineralization at an average grade of 1.98% U 3O8 and inferred resources of 40.7 million pounds U 3O8
based on 161,600 tonnes of mineralization at an average grade of 11.43% U 3O8.
For more information on the J Zone deposit, please refer to the Technical Report on the Mineral Resource
Estimate on the J Zone Uranium Deposit, Waterbury L ake Property dated September 6, 2013 by Allan
Armitage, Ph. D., P. Geo, and Alan Sexton, M.Sc., P .Geo, of GeoVector Management Inc. available on
Denison’s website and under the Company’s profile on SEDAR (www.sedar.com). For further details on
the Roughrider deposit, prior to acquisition by Rio Tinto in 2012, please refer to the Preliminary Eco nomic
Assessment Technical Report for the East and West Z ones Roughrider Uranium Project, Saskatchewan
dated September 13, 2011 by SRK Consulting (Canada) Inc. available under Hathor Exploration Limited’s
profile on SEDAR.
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.
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
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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, 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 .
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.
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Figure 1: Location of summer 2017 drill collars on Denison’s Waterbury Lake project.
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Figure 2: Simplified basement geology map of the Huskie zone at the sub-Athabasca unconformity.
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Figure 3: Simplified cross-section along the westernmost fence of drill hole (looking west).