Denison Announces 88% Increase IN Indicated Resources at Wheeler River with Updated Mineral Resource Estimate FOR the Gryphon Deposit
Denison Mines Corp.
1100 – 40 University Ave
Toronto, ON M5J 1T1
www.denisonmines.com
@DenisonMinesCo
PRESS RELEASE
DENISON ANNOUNCES 88% INCREASE IN INDICATED RESOURCES AT
WHEELER RIVER WITH UPDATED MINERAL RESOURCE ESTIMATE
FOR THE GRYPHON DEPOSIT
Toronto, ON – January 31, 2018 Denison Mines Corp. (“Denison” or the “Company”) (TSX: DML) (NYSE
MKT: DNN) (NYSE American: DNN) is pleased to announ ce an 88% increase in the Indicated Mineral
Resources estimated for the Wheeler River project. Denison is also pleased to announce it has increase d
its interest in the Wheeler River project during 20 17 from 60% to 63.3% in accordance with an agreemen t
with its Wheeler River Joint Venture partners, as previously announced on January 10, 2017. The updated
mineral resource estimate for Wheeler River is highlighted by a significant increase in the estimated mineral
resources for the property’s basement-hosted Gryphon uranium deposit.
Resource Update Highlights:
• The Gryphon deposit is estimated to contain, above a cut-off grade of 0.2% U 3O8, 61.9 million pounds
of U 3O8 (1,643,000 tonnes at 1.71% U 3O8) in Indicated Mineral Resources, plus 1.9 million pounds
of U 3O8 (73,000 tonnes at 1.18% U 3O8) in Inferred Mineral Resources.
• Wheeler River is also host to the Phoenix deposit, which is estimated to include Indicated Mineral
Resources of 70.2 million pounds of U 3O8 above a cut-off grade of 0.8% U 3O8 (166,000 tonnes at
19.1% U3O8), as disclosed in the Preliminary Economic Assessm ent for the Wheeler River Uranium
Project, Saskatchewan, Canada dated March 31, 2016 and prepared by Ken Reipas, P.Eng of SRK
Consulting (Canada) Inc. (the “PEA”).
• With this update to the resources estimated for th e Gryphon deposit, the combined Indicated Mineral
Resources estimated for Wheeler River have increased by 88% to 132.1 million pounds U 3O8, which
will be used to support the Pre-Feasibility Study ( "PFS") initiated for the project in July 2016 and
expected to be completed during 2018.
Wheeler River Property Mineral Resource Estimate Summary,
including the updated mineral resource estimate for the Gryphon deposit
as of January 30, 2018 (the “Effective Date”)
Deposit Category Tonnes Grade
(% U3O8)
Million lbs U3O8
(100% Basis)
Million lbs U3O8
(Denison 63.3 %)
Gryphon Indicated 1,643,000 1.7 61.9 39.2
Phoenix Indicated 166,000 19.1 70.2 44.4
Total Indicated 1,809,000 3.3 132.1 83.6
Gryphon Inferred 73,000 1.2 1.9 1.2
Phoenix Inferred 9,000 5.8 1.1 0.7
Total Inferred 82,000 1.7 3.0 1.9
Notes:
1. CIM Definitions (2014) were followed for classif ication of Mineral Resources.
2. Mineral Resources for the Gryphon deposit are re ported above a cut-off grade of 0.2% U 3O8. See detailed results below for
additional notes related to the Mineral Resources estimated for the Gryphon deposit.
3. Mineral Resources for the Phoenix deposit are re ported above a cut-off grade of 0.8% U3O8. Mineral Resources for the Phoenix
deposit were last estimated in 2014 to reflect the expansion of the high-grade zone. As no new drillin g has been completed at
Phoenix since that time, the mineral resource estimates for the Phoenix deposit remain current.
4. Numbers may not add due to rounding.
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David Cates, President and CEO of Denison commented, "This updated resource estimate for Gryphon
marks an important milestone for the Wheeler River project – solidifying its ranking as the largest
undeveloped uranium project in the infrastructure r ich eastern Athabasca Basin, and positioning
the project to be the next new mine developed in th e region. The long-term fundamentals for the
uranium mining business are certainly at the forefr ont of the market right now, with a series of
production curtailments recently being announced. As a developer positioning to build a new mine
for the next uranium bull market, we strongly belie ve that the ability to leverage existing
infrastructure, and limit up-front costs and timeli nes to production, will make the difference in
building and financing a new mine as the uranium ma rket strengthens. This updated resource, is
expected to bode well for our ongoing efforts related to the Wheeler River PFS, which is planned to
be completed during 2018."
Dale Verran, Vice President Exploration of Denison commented, “The results of this updated mineral
resource estimate validates how the Gryphon deposit has continued to grow in size and confidence
– having converted more than 100% of the inferred resources previously estimated for the A, B and
C series lenses into indicated resources, and intro ducing an initial estimate of mineralization for
the D and E series lenses. With over 97% of the tot al resources for the project classified as
indicated, we have turned our focus in 2018 to step -out drilling where the Gryphon deposit offers
numerous expansion opportunities – including along strike of the new D and E series lenses.”
The updated mineral resource estimate for the Gryph on deposit was prepared for the Company by RPA
Inc. ("RPA") in accordance with CIM Definition Standards (2014) in National Instrument 43-101 – Standards
of Disclosure for Mineral Projects (“NI 43-101”).
Wheeler River Highlights
• Largest undeveloped high-grade uranium project in t he eastern Athabasca: With the updated
mineral resource estimate for the property’s Gryphon deposit, the Wheeler River project retains and
improves its position as the largest undeveloped high-grade uranium project in the eastern portion of
the Athabasca Basin region, in northern Saskatchewa n. The property is host to two high-grade
uranium deposits discovered by Denison – namely the basement-hosted Gryphon deposit and the
unconformity-hosted Phoenix deposit, which ranks as the highest grade undeveloped uranium
deposit known in the world.
• Proximal to existing uranium mining and milling inf rastructure: The property is located in the
infrastructure rich eastern portion of the Athabasc a Basin, which is host to existing uranium mining
and milling infrastructure, including the 22.5% Denison owned McClean Lake mill. The Wheeler River
property lies alongside provincial highway 914 and a provincial powerline that run between the
McArthur River mine and the Key Lake uranium mill.
• Positive preliminary project economics: On April 4, 2016, Denison announced the results of its
Preliminary Economic Assessment ("PEA”) for the Whe eler River Project, which considers the
potential economic merit of co-developing the high-grade Gryphon and Phoenix deposits as a single
underground mining operation. The PEA was based on the resources estimated at the Gryphon
deposit in late 2015, and returned a base case pre-tax Internal Rate of Return ("IRR") of 20.4% based
on the then current long term contract price of uranium (US$44.00 per pound U 3O8). Denison's share
of initial capital expenditures ("CAPEX") in the PE A is estimated to be CAD$336M (CAD$560M on
100% ownership basis). The PEA is preliminary in nature, was based on Inferred Mineral Resources
that are considered at the time to be too speculative geologically to have the economic considerations
applied to them to allow them to be categorized as mineral reserves, and there is no certainty that
the results from the PEA will be realized. The upd ated estimate of Indicated Mineral Resources for
the project of 132.1 million pounds U3O8 will support the PFS expected to be completed in 2018.
• Increasing Denison ownership: The project is a joint venture between Denison (63. 3% and
operator), Cameco Corp. (“Cameco”) (26.7%), and JCU (Canada) Exploration Company Limited
(“JCU”) (10%). In January 2017, Denison entered int o an agreement with its Wheeler River Joint
Venture partners to fund 75% of Joint Venture expen ses in 2017 and 2018 (ordinarily 60%) in
exchange for an increase in Denison's interest in t he 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.
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• Significant potential for resource growth: The Gryphon deposit is a growing, high-grade uranium
deposit that belongs to a select group of large bas ement-hosted uranium deposits in the eastern
Athabasca Basin, which includes Cameco’s Eagle Point mine and Millennium deposit, and Rio Tinto's
Roughrider deposit. The Gryphon deposit remains open in numerous areas with significant potential
for future resource growth. Priority target areas i nclude: (1) Along strike to the northeast of the E
series lenses, where both unconformity and basement potential exists; (2) Down plunge of the A and
B series lenses; (3) Along strike to the northeast and southwest of the D series lenses; and (4) Within
the currently defined D series lenses, where additional high-grade shoots may exist.
In addition, very little regional exploration has taken place on the property in recent years, with drilling
efforts focussed on Phoenix and Gryphon, which were discovered in 2008 and 2014 respectively.
The property is host to numerous uranium-bearing li thostructural corridors which are under- or
unexplored and have the potential for additional large, high-grade unconformity or basement hosted
deposits. Exploration drilling is warranted along these corridors to follow-up on previous mineralized
drill results, or to test geophysical targets identified from past surveys.
Details of the Updated Mineral Resource Estimate for the Gryphon Deposit
Updated Mineral Resource Estimate
The Gryphon deposit was discovered in March 2014 and, following the completion of 66 drill holes (40,864
metres of drilling) on an approximate 50 x 50 metre spacing, a maiden resource estimate was completed
by RPA in September 2015. The maiden estimate was c omprised of Inferred Mineral Resources of 43.0
million pounds of U 3O8 above a cut-off grade of 0.2% U 3O8 (834,000 tonnes at 2.3% U 3O8) and included
the deposit’s A, B and C series lenses.
The updated mineral resource estimate, reported her ein, was completed by RPA – a recognized
independent consulting firm with significant resour ce estimation experience in high-grade Athabasca
uranium deposits. For the updated mineral resource estimate, RPA used data collected from eight diamond
drilling campaigns completed during the last four years, including a total of 117,788 metres of drilling in 210
drill holes. The updated mineral resource estimate includes the expanded A and B series lenses, C seri es
lenses, and the recently delineated D and E series lenses, as detailed in the table below.
Mineral Resource Estimate for the Gryphon Deposit
with an Effective Date of January 30, 2017 (100% basis)
Lens Category Tonnes Grade
(% U 3O8)
Million lbs U 3O8
(100% Basis)
A1HG Indicated 148,000 7.60 24.72
A1 Indicated 365,000 0.84 6.74
A2 Indicated 262,000 0.96 5.52
A3 Indicated 36,000 0.38 0.30
B1 Indicated 161,000 1.05 3.74
B2 Indicated 158,000 1.50 5.24
B3 Indicated 59,000 1.33 1.71
C1 Indicated 105,000 1.19 2.74
D1HG_HW Indicated 17,000 5.00 1.82
D1HG_MD Indicated 11,000 7.37 1.80
D1HG_FW Indicated 15,000 7.52 2.47
D1 Indicated 153,000 0.58 1.95
D4 Indicated 89,000 0.74 1.45
E2 Indicated 65,000 1.15 1.66
Total Indicated 1,643,000 1.71 61.86
A4 Inferred 2,000 0.34 0.01
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B5 Inferred 10,000 0.25 0.05
D2 Inferred 5,000 0.40 0.04
D3 Inferred 13,000 1.19 0.35
E1 Inferred 31,000 1.30 0.88
E2 Inferred 12,000 2.01 0.54
Total Inferred 73,000 1.18 1.89
Notes:
1. CIM Definitions (2014) were followed for classif ication of mineral resources.
2. Mineral Resources are estimated at an incrementa l cut-off grade of 0.2% U 3O8 using a long-term uranium price of US$50
per lb, and a US$/C$ exchange rate of 0.75. The cut-off grade is based on incremental operating costs for low-grade
material.
3. A minimum mining width of 2 metres was used.
4. Bulk density is derived from grade using a formu la based on 279 measurements.
5. High grade mineralization was capped at 30% U 3O8 and restricted at 20% U3O8 for the A1HG and capped at 20% U 3O8 for
the D1HG with no search restrictions.
6. Low grade mineralization was capped at 20% U 3O8 for the C1 domain with search restrictions applied to U 3O8 grades greater
than or equal to 10.0% U 3O8.
7. Low grade mineralization was capped at 15% U 3O8 for the B1, B2, E1 and E2 domains with search rest rictions applied to
U3O8 grades greater than or equal to 10.0% U 3O8 for the B1 domain and 5.0% U 3O8 for the E2 domain.
8. Low grade mineralization was capped at 10% U 3O8 for the A1-A4, B3-B7, C4-C5, and D2-D4 domains wit h no search
restrictions.
9. Low grade mineralization was capped at 5% U 3O8 for the D1 domain with no search restriction
10. Numbers may not add due to rounding.
Geology and Mineralization
The Gryphon uranium deposit occurs within southeast erly dipping crystalline basement rocks of the
Wollaston Supergroup below the regional sub-Athabas ca Basin unconformity. The deposit is located from
520 to 850 metres below surface and has an overall strike length of 610 metres, dip length of 390 metr es
and varies in thickness between 2 and 70 metres, depending on the number of mineralized lenses present.
The mineralized lenses are controlled by reverse fa ult structures which are largely conformable to the
basement stratigraphy and dominant foliation. The A , B and C series of lenses comprise stacked, parall el
lenses which plunge to the northeast along a fault zone (“G-Fault”) which occurs between hanging wall
graphite-rich pelitic gneisses and a more competent pegmatite-dominated footwall. A ubiquitous zone of
silicification (“Quartz-Pegmatite Assemblage”) straddles the G-Fault and the A, B and C series of lens es
occur hanging wall, within, and footwall to the Quartz-Pegmatite Assemblage respectively. The D series of
lenses occur within the pegmatite-dominated footwall along a secondary fault zone (“Basal Fault”) or within
extensional relay faults which link to the G-Fault. The E series of lenses occur along the G-Fault, up -dip
and along strike to the northeast of the A and B se ries lenses, within the upper basement or at the su b-
Athabasca unconformity. Mineralization within the Gryphon deposit lenses is dominated by massive, semi-
massive or fracture-hosted uraninite associated with an alteration assemblage comprising hematite, dravitic
tourmaline, illite, chlorite and kaolinite. Seconda ry uranium minerals, including uranophane and carno tite,
and sulphides are trace in quantity.
Drilling, Sampling and Assay Procedures
The updated mineral resource estimate for the Gryphon deposit, reported herein, is based on a total of 210
drill holes. Drill collars were surveyed in the field utilizing a Differential Global Positioning System (“DGPS”)
and the trajectory of all drill holes was determine d with a Reflex survey instrument in single point m ode,
which measures the dip and azimuth at 50 metre inte rvals down the hole. Denison employed a directional
drilling method to improve drilling accuracy and 12 0 of the 210 drill holes were completed as subsurfa ce
‘daughter’ holes which were drilled as off-cuts from surface ‘parent’ holes.
Drill core with anomalous total gamma radioactivity (>300 counts per second utilizing 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.
Uranium assays are performed by the Saskatchewan Re search Council ("SRC") Geoanalytical
Laboratories using an ISO/IEC 17025:2005 accredited method for the determination of U 3O8 weight %.
Sample preparation involves crushing and pulverizin g core samples to 90% passing -106 microns. The
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resultant pulp is digested using aqua-regia and the solution analyzed for U 3O8 weight % using ICP-OES.
Other major and trace elements are determined using ICP-MS or ICP-OES after partial and total digestions.
Boron values are obtained through NaO 2/NaCO 3 fusion followed by ICP-OES. In addition to internal checks
by SRC Geoanalytical Laboratories, the Company has rigorous quality assurance and quality control
("QAQC") procedures including the insertion of stan dard reference materials, blanks and field duplicat es.
The assay data is subject to verification procedure s by qualified persons employed by Denison prior to
disclosure. Core recovery at Gryphon is typically 1 00% and therefore radiometric equivalent U 3O8 grades
("eU3O8") are seldom required as a substitute for chemical U 3O8 assays. For the updated Gryphon mineral
resource estimate, reported herein, 6.5 % of the as say intervals relied on eU 3O8 grades where core
recovery was less than 80%. For further details on the assay, QAQC and data verification procedures
please see Denison's Annual Information Form dated March 23, 2017 filed under the Company's profile on
SEDAR (www.sedar.com).
Estimation Methodology
The three-dimensional mineralized wireframes were c reated by Denison utilizing Gemcom software
following detailed interpretation of the deposit geology and structure. The wireframes were defined using a
threshold of 0.05% U 3O8 and minimum thickness of two metres. One higher gr ade domain was defined
within the A1 lenses and three higher grade domains were defined in the D1 lenses based on a threshold
of 4.0% U 3O8. The wireframes and drilling database were sent to RPA for grade modelling following QAQC
which included ensuring the wireframes were ‘snapped’ to the drill hole mineralized intervals.
Based on 279 dry bulk density determinations, a pol ynomial formula was determined relating bulk densit y
to uranium grade which was used to assign a density value to each assay. Bulk density values were used
to weight grades during the resource estimation process and to convert volume to tonnage. Uranium grade
multiplied by density (GxD) values and density (D) values were interpolated into blocks measuring 5 metres
by 1 metre by 2 metres using an inverse distance sq uared (ID 2) algorithm since variograms were not
considered good enough to derive kriging parameters . Hard domain boundaries were employed at the
wireframe edges, so that blocks within a given wire frame were only informed by grade data from that
wireframe. For the A1 high-grade domain, assays wer e capped at 30% U 3O8 with a search restriction
applied to composite grades over 20% and for the D1 high-grade domains, assays were capped at 20%
U3O8 with no search restriction. For the A1-A4, B3-B7, C4-C5 and D2-D4 low-grade domains, assays were
capped at 10% U 3O8. For the C1 low-grade domain, assays were capped at 20% U 3O8 with a search
restriction applied to composite grades over 10%. F or the B1, B2, E1 and E2 low-grade domains, assays
were capped at 15% U 3O8 with search restrictions applied to composite grade s over 10% U 3O8 for the B1
domain and 5.0% U3O8 for the E2 domain. For the D1 low-grade domain, assays were capped at 5% U3O8.
Block grade was derived from the interpolated GxD value divided by the interpolated D value for each block.
Block tonnage was based on volume times the interpolated D value.
The mineral resource estimate for the Gryphon depos it was classified according to the drill hole spaci ng
and the apparent continuity of mineralization, as e ither Indicated Mineral Resources (generally, drill hole
spacing of 25 x 25 meters) or Inferred Mineral Reso urces (generally, drill hole spacing of 50 x 50 met res).
The block models were validated by comparison of do main wireframe volumes with block volumes, visual
comparison of composite grades with block grades, c omparison of block grades with composite grades
used to interpolate grades, and comparison with estimation by a different method.
Updated Wheeler River Technical Report
RPA, an independent technical consulting firm, was retained by Denison on behalf of the Wheeler River
Joint Venture to prepare the updated mineral resour ce estimate for the Gryphon deposit. An updated
independent Technical Report will be prepared for t he Wheeler River Project, including both the Grypho n
and Phoenix deposits, and will be filed on SEDAR (www.sedar.com) within 45 days of this news release.
Qualified Persons
The Mineral Resource Estimate was prepared by Mr. M ark Mathisen, C.P.G., Principal Geologist at RPA
and Mr. William Roscoe, PhD, P. Geo, Principal Geol ogist at RPA, who read and approved the related
disclosure about the mineral resources in this pres s release. Both are independent Qualified Persons i n
accordance with the requirements of NI 43-101.
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The technical information contained in this release has been reviewed and approved by Mr. Dale Verran,
MSc, P.Geo, Pr.Sci.Nat., Denison's Vice President, Exploration, who is also a Qualified Person in
accordance with the requirements of NI 43-101.
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 (63.3% and operator), Cameco Corp. (“Cameco ”) (26.7%), and JCU (Canada) Exploration
Company Limited (“JCU”) (10%), and is host to the h igh-grade Gryphon and Phoenix uranium deposits
discovered by Denison in 2014 and 2008, respectively.
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.
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% interes t in the project. Pursuant to the agreement, as at
December 31, 2017, Denison has increased its interest in the Wheeler River project from 60% to 63.3%.
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
hosts the high-grade Phoenix and Gryphon uranium de posits, Denison's exploration portfolio consists of
numerous projects covering approximately 347,000 he ctares in the Athabasca Basin region, including
327,000 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 and Midwest
A deposits, and a 64.22% interest in the J Zone dep osit and Huskie discovery on the Waterbury 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
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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; plans and objectives with respect to updating its resource estimates and preparing a PFS to assess on a
preliminary basis the potential for mine development an whether to proceed with a detailed feasibility study; and Denison’s percentage
interest in its properties and its plans and agreem ents 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. Factors, such as
environmental impacts, stakeholder approvals, and capital needs can significant alter plans and achievements. 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 .
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 of the Wheeler River property.