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Cypress Development Files Resource Estimate FOR Clayton Valley Lithium Project, Nevada

Resource Estimates

Suite 1610 - 777 Dunsmuir Street, Vancouver, BC, Canada, V7Y 1K4

www.cypressdevelopmentcorp.com

TSX Venture Exchange Symbol: CYP

Email: [email protected]

Telephone: (604) 687-3376

Facsimile: (604) 687-3119

NEWS RELEASE

June 11, 2018

CYPRESS DEVELOPMENT FILES RESOURCE ESTIMATE FOR

CLAYTON VALLEY LITHIUM PROJECT, NEVADA

Vancouver, BC - Cypress Development Corp. (TSX-V: CYP) (OTCQB: CYDVF)

(Frankfurt: C1Z1) (“Cypress” or the “Company”) is pleased to announce it has filed a

National Instrument (NI) 43 -101 Technical Report on SEDAR titled “ Resource

Estimate Clayton Valley Lithium Project ". The Technical Report details the

independent Mineral Re source Estimate for the Company’s 100% -owned lithium

project in Nevada, as described in the Company’s press release of May 1, 2018.

Global Resource Engineering (GRE) of Denver, Colorado, prepared th e Technical

Report which is the first estimate of resources for Cypress’ property . The report

carries an Effective Date of May 1, 2018 and Issue Date of Jun e 5, 2018. The report

includes recommendations for further work including a Preliminary Economic

Assessment (PEA) which GRE expects to complete in the next two months. Terre A.

Lane, J. Todd Harvey, Hamid Samari, and J. J. Brown of GRE are the Qualified

Persons for the report.

Highlights:

 Total Indicated Mineral Resource of 697 million tonnes at an average

grade of 886 ppm Li, or 3.287 million tonnes of lithium carbonate

equivalent (LCE).

 Total Inferred Mineral Resource of 643 million tonnes at an average

grade of 852 ppm Li, or 2.916 million tonnes of LCE.

 The mineral resources are reported using a cut -off grade of 300 ppm Li

and constrained to pit shell reflecting a $15/tonne operating cost,

$10,000/tonne of LCE price and 80% net recovery to LCE.

 Minor changes in the resource model occurred following the May 1, 2018

press release due to adjustments in model boundaries. The proportion of

indicated to inferred tonnes increased somewhat while the net lithium

tonnes in the model decreased slightly.

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 The resources are broken down into five units which are distinguished by

stratigraphic position and color (Table 1). The middle three units are

higher grade and estimated to average greater than 950 ppm Li, whereas

the uppermost and lowermost units average less than 700 ppm Li.

 GRE generated an initial pit outline capable of supporting several

decades of mining at a production rate of 10,000 to 15,000 tpd (Table 2).

The initial pit contains an indicated resource of 191 million tonnes

averaging 988 ppm Li (1.007 million tonnes LCE), and an inferred

resource of 25 million tonnes at 1,047 ppm Li, (0.142 million tonnes LCE).

Selective mining of higher grade material, i.e. targeting the middle three

units, will be an option considered in the PEA.

 Metallurgical bench tests from three drill holes, two of which are within the

initial pit area, indicate agitated tank leaching with sulfuric acid is a viable

method for extracting lithium. Tests indicate leach times of under 8 hours

with relatively low consumptions of acid a nd other reagents. Sulfuric acid

is expected to be the major component in operating costs, and

alternatives for acid supply will be considered in the PEA.

 Five to ten drill holes in the initial pit area are recommended by GRE to

convert resources into hig her confidence categories and to obtain

material for further metallurgical testing. This drilling is not required for the

PEA but recommended to advance the project quickly. GRE additionally

recommends proceeding with collecting environmental baseline data, and

conducting hydrogeology and geotechnical studies.

Details of the Mineral Resource Estimate

GRE estimated the Mineral Resource using a database of 23 drill holes for 1,891

metres, drilled by Cypress during 2017 and 2018. The resource was calculated using

a 2.5-dimensional (2.5D) gridded model (common for layered sedimentary deposits)

of six mineralized stratigraphic units , which includes a thin surficial gravel unit, and

verified using a 3 -dimensional (3D) block model. The mineralized intercept s in the

drill holes and a 3D interpretation of the geology and intercepts were done by Terre

Lane and J.J. Brown of GRE, who are Qualified Persons under NI 43-101.

Clayton Valley Lithium Project 3D Drill Hole View:

https://www.cypressdevelopmentcorp.com/site/assets/files/3573/cyp_re_3d_dh_view

.jpg

All samples for the project were assayed at ALS Chemex or Bureau Veritas, both

ISO-9000 certified laboratorie s. The resulting assay intervals were composited for

the entire sedimentary unit for the 2.5D gridded model and were composited to a 5m

down-hole length for the 3D estimate. Grade capping of lithium values was not

required. Model grades were interpolated i n Techbase using an inverse distance

squared algorithm. A tonnage factor of 1.7 tonnes per cubic meter was selected

based upon general published values to represent the insitu density. Indicated

Mineral Resources were defined as being within 300 meters of a drill hole, with the

Inferred mineralization requiring 2 drill holes within a search ellipse of 1500 x 800

metres for each unit. The major axis was orientated north -south along valley. The

sedimentary units were truncated at the Angel Island volcanic pac kage and claim

boundaries.

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The mineral resources reported use a cut -off grade of 300 ppm Li, reflecting a

$15/tonne operating cost for mining, processing and G&A. The costs reflect a 10,000

– 15,000 tonne per day mining operation in soft sedimentary mate rial that does not

require blasting. Cost assumptions for the cut-off grade include a delivered acid cost

of $80/tonne and 100 kg acid per tonne of material processed.

An overall lithium recovery of 80% was employed for the mineral resource based on

the results from laboratory testing and confirmation leach testing at Hazen in Golden,

Colorado under direction of Dr. Todd Harvey, who is Qualified Person in Metallurgy

under NI 43-101 from GRE. The preliminary metallurgical examinations indicate that

the cl aystone responds well to conventional weak acid leaching with no upstream

size reduction required. Initial results indicate that lithium extractions of greater than

80% can be achieved. Expected leach conditions of 2 – 8 hours of leaching with 5%

sulfuric acid at temperatures ranging between 50 and 80 °C are anticipated.

Clayton Valley Lithium Project Leach Kinetics:

https://www.cypressdevelopmentcorp.com/site/assets/files/3573/cyp_re_preliminary_

leach_kinetics-1.jpg

The preliminary leach results indicate relatively high grade pregnant leach solution

(PLS) can be produced containing Li, K, Na and limited deleterious elements and a

conventional downstream lithium recovery circuit should be applicable to produce

saleable lithium carbonate or lithium hydroxide.

Clayton Valley Lithium Project Conceptual Production Flowsheet:

https://cypressdevelopmentcorp.com/site/assets/files/3573/cyp_re_conceptual_flows

heets.jpg

GRE concludes Cypress’ Clayton Valley Lithium P roject has the potential to be a

major supplier of lithium products in the world, and additional work is warranted.

Table 1. Indicated and Inferred Resources

Lithology Tonne Grade-ppm Li-kg LCE-kt

Indicated

Upper Tuff 58,700 707 41,500 221

Upper Olive 148,300 897 133,000 708

Main Blue 220,500 1,081 238,400 1,269

Lower Olive 132,200 851 112,500 599

Hard Bottom 136,900 673 92,100 490

Total 696,600 886 617,500 3,287

Inferred

Upper Tuff 65,300 689 45,000 240

Upper Olive 112,400 883 99,300 529

Main Blue 190,700 1,032 196,800 1,048

Lower Olive 149,400 833 124,400 662

Hard Bottom 125,000 657 82,100 437

Total 642,800 852 547,600 2,916

Note: ppm = parts per million, Li = lithium metal, LCE = lithium carbonate equivalent,

kg = kilogram, kt = kilotonne

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Clayton Valley Lithium Project Resource Cross Section:

https://www.cypressdevelopmentcorp.com/site/assets/files/3573/cyp_re_cross_secti

on_2.jpg

Table 2. Resources within Initial Pit Outline

Lithology Tonne Grade-ppm Li-kg LCE-kt

Indicated

Upper Tuff 22,600 686 15,500 83

Upper Olive 37,400 947 35,400 188

Main Blue 88,000 1,169 102,900 548

Lower Olive 24,500 922 22,600 120

Hard Bottom 18,900 672 12,700 68

Total 191,400 988 189,100 1,007

Inferred

Upper Tuff - - - -

Upper Olive 7,200 986 7,100 38

Main Blue 11,200 1,161 13,000 69

Lower Olive 7,000 929 6,500 35

Hard Bottom - - - -

Total 25,400 1,047 26,600 142

Clayton Valley Lithium Project Plan View of Preliminary Pit:

https://www.cypressdevelopmentcorp.com/site/assets/files/3573/cyp_re_plan_view_

of_preliminary_pitsm.jpg

CIM definitions were followed for Mineral Resources. Mineral R esources are not

Mineral Reserves and do not have demonstrated economic viability. There is no

certainty that all or any part of the Mineral Resources will be converted into Mineral

Reserves.

Terre Lane, J.J. Brown , Hamid Samari and Dr. Todd Harvey, of GR E are the

Qualified Persons as defined by National Instrument 43 -101 and have approved of

the technical information in this release.

About Cypress Development Corp.:

Cypress Development Corp. is a publicly traded exploration company focused on

developing the Company's 100%-owned Clayton Valley lithium project in the State of

Nevada, U.S.A.

Cypress' Clayton Valley Lithium Project is located immediately east of Albemarle's

Silver Peak mine, North America's only lithium brine operation. Recent exploration by

Cypress has discovered an extensive deposit of lithium -bearing claystone adjacent

to the brine field. With mineralization tested by drilling over a seven -kilometer trend,

the size of the deposit makes Clayton Valley a premier target that has the potential to

impact the future of lithium production in North America.

Cypress Development Corp. has approx. 60.1 million shares issued and outstanding.

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To find out more about Cypress Development Corp. (TSX-V: CYP), visit our website

at www.cypressdevelopmentcorp.com.

CYPRESS DEVELOPMENT CORP.

“Dr. Bill Willoughby”

WILLIAM WILLOUGHBY, PhD., PE

Chief Executive Officer

For further information contact myself or:

Don Myers

Cypress Development Corp.

Director, Corporate Communications

Telephone: 604-639-3851

Toll Free: 800-567-8181

Facsimile: 604-687-3119

Email: [email protected]

NEITHER THE TSX VENTURE EXCHANGE NOR ITS REGULATION SERVICES

PROVIDER ACCEPTS RESPONSIBILITY FOR THE ADEQUACY OR ACCURACY OF THE

CONTENT OF THIS NEWS RELEASE.

This release includes certain statements that may be deemed to be "forward -looking

statements". All statements in this release, other than statements of historical facts, that

address events or developments that management of the Company expects, are forward -

looking statements. Although management believes the expectations expressed in such

forward-looking statements are based on reasonable assumptions, such statements are not

guarantees of future performance, and actual results or developments may differ materially

from those in the forward -looking statements. The Company undertakes no obli gation to

update these forward -looking statements if management's beliefs, estimates or opinions, or

other factors, should change. Factors that could cause actual results to differ materially from

those in forward -looking statements, include market prices, exploration and development

successes, continued availability of capital and financing, and general economic, market or

business conditions. Please see the public filings of the Company at www.sedar.com for

further information.