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International Tower Hill Mines Announces Pre-Feasibility Study Results on 13.6 Million Ounce Gold Resource Reaffirms Project’s Excellent Leverage To Rising Gold Prices Increased 13.6 Million Ounce Resource Solidifies Standing As Largest

Economic Studies

Suite 2710 – 200 Granville Street

Vancouver, BC

Canada V6C 1S4

Tel: 604.683.6332

Fax: 604.408.7499

www.ithmines.com

NR21-06 November 4, 2021

International Tower Hill Mines Announces

Pre-Feasibility Study Results on 13.6 Million Ounce Gold Resource

Reaffirms Project’s Excellent Leverage To Rising Gold Prices

Increased 13.6 Million Ounce Resource Solidifies Standing As Largest

Independent Gold-Only Resource in North America

Annual Average Production of 306,200 Ounces per Year Over 21 Year Mine Life

Significantly De-Risks Project and Forms Solid Foundation To Advance Project Forward

Vancouver, British Columbia, November 4, 2021 – I n t e rnational Tower Hill Mines Ltd. (“ITH” or the

“Company”) (TSX: ITH; NYSE-MKT: THM) today announced the result s of the Pre-Feasibility Study (the

“PFS”) for its Livengood Gold Project (the “Project”) located near Fairbanks, Alaska. The PFS details a project

that would process 65,000 tons per day and produce 6.4 million ounces of gold over 21 years from a gold

resource estimated at 13.6 million ounces at 0.60 g/tonne. The PFS utilized a third-party review by Whittle

Consulting and BBA Inc. to integrate new interpretations based on an expanded geological database, improved

geological modelling, new resource estimation methodology, an optimized mine plan and production schedule,

additional detailed metallurgical work at various gold grades a nd grind sizes, changes in the target grind for

the mill, new engineering estimates, and updated cost inputs, all of which significantly de-risk the Project. The

PFS has estimated the capital costs of the Project (“CAPEX”) at US$1.93 billion, the total cost per ton milled

(“OPEX”) at US$13.12, the all-in sustaining costs (“AISC”) at US$1,171 per ounce, and an after-tax NPV(5%)

of US$400 million at $1,800/oz, US$975 million at US$2,000/oz, and US$2.3 billion at $US2,500/oz.

“This PFS confirms that the Livengood Gold Project is the one o f the largest, highly leveraged gold projects

in North America. This study is the culmination of years of wor k and greatly enhances our understanding of

the deposit. We have now thoroughly evaluated, optimized, and d e-risked all major elements of the Project

and have an excellent foundation on which to build shareholder value. International Tower Hill’s estimated

13.6 million ounces, together with our favorable jurisdiction a nd proximity to infrastructure, offers our

investors great leverage to the gold price.” said Karl Hanneman, CEO.

The Company invites you to attend a conference call and webcast hosted by CEO Karl Hanneman to discuss

the Company and this news release.

Conference Call & Webcast Details:

Date: Novembe r 5, 2021 at 12:00 pm ET

Webcast: https://services.choruscall.com/links/thm211105.html

North American callers: 1-877-270-2148

International callers: 1-412-902-6510

International Tower Hill Mines Ltd. - 2 - November 4, 2021

NR21-06 Continued

Pre-Feasibility Study Overview

The Project configuration evaluated in the PFS is a conventional, owner-operated surface mine that will utilize

large-scale mining equipment in a blast/load/haul operation. Mill feed would be processed in a 65,000 tons per

day comminution circuit consisting of primary and secondary crushing, wet grinding in a single semi-autogenous

(SAG) mill and single ball mill followed by a gravity gold circuit and a conventional carbon in leach (CIL) circuit.

Whittle Enterprise Optimization

Prior to beginning the PFS, the Company retained Whittle Engineering and BBA Engineering to collaborate on

an enterprise optimization study (the “Whittle and BBA Study”) to review various technologies and project

configurations and to recommend the optimum configuration for the PFS. The Whittle and BBA Study reviewed

secondary crushing with SAG and ball mill, tertiary crushing with ball mill, gravity/CIL at P80 of 90 micron to

250 micron, stand-alone and auxiliary heap leach configurations, gravity only gold recovery, gravity/flotation

with pressure oxidation and CIL of flotation concentrate. These configurations were evaluated at various

combinations of project ramp up strategy, annual throughput, primary, secondary, and tertiary grind size, as well

as mining fleet size and stockpile management strategies. Tailings technologies reviewed included conventional

tailings and pressure filtered tailings.

The Whittle and BBA Study determined that the gravity/CIL plant at P80 250 micron with conventional tailings

provided the highest NPV, which is the configuration detailed in the PFS.

Pre-Feasibility Study Summary

The PFS was prepared by independent third-party consultants and provides information on the optimized Project

with higher throughput, an updated resource estimate, and capital and operating cost estimates as compared to

the project evaluated in the National Instrument 43-101 - Standards of Disclosure for Mineral Projects (“NI 43-

101”) April 2017 Technical Report (the “2017 Report”). The fina l version of the NI 43-101 technical report

containing the PFS will be filed on SEDAR within 45 days. As a result of the changes to the Project as evaluated

in the PFS, including differences in the mineral resource estimation methodology and changes to the economic

parameters applied to the geologic block model (gold price, recovery, CAPEX, and OPEX), all of which resulted

in a change in the mineral resources, the Project as evaluated in the 2017 Report is no longer considered current

and the 2017 Report should therefore not be relied upon by investors.

The Company cautions that the PFS is preliminary in nature, and is based on technical and economic assumptions

which would be further refined and evaluated in a full feasibility study. The PFS is based on an updated Project

mineral resource estimate effective as of August 20, 2021 using a different mineral resource model than what

was used in the 2017 Report.

The following is a summary of the material aspects and assumptions of the PFS. Investors are urged to review

the complete NI 43-101 report following its filing on SEDAR for complete details of the PFS.

The engineering design to estimate capital costs used in the PFS are within a -20%/+25% accuracy.

Project Location

The Project is connected by an exi sting paved highway to the ci ty of Fairbanks, 70 miles to the southwest in

central Alaska. The Project is located in an active mining district that has been mined for gold since 1914. The

State of Alaska land use plan designates mining as the primary surface land use for the area in which the Project

is located. Employees would be bussed daily to the site from Fairbanks.

International Tower Hill Mines Ltd. - 3 - November 4, 2021

NR21-06 Continued

Infrastructure

The Project would include a line d tailings management facility, an administration o ffice/shop/warehouse

complex, and would also include construction of a 50-mile 230kV electrical transmission line to the mine site

from the existing grid power near Fairbanks, Alaska.

Environmental and Community Relations

Twelve continuous years of baseline environmental work continue s to indicate that all aspects of the Project

can be successfully and safely managed. The design of the tailings facility incorporates best practices including

a lined rock fill structure with a lined tailings basin. The Project development team has considerable experience

working with Alaska’s large mine permitting process and has a proven and respected track record of developing

mining projects safely and in an environmentally sound manner. The Project has already and will continue to

provide local economic opportunities with local access to a hig hly skilled and available work force. The

Company is also working to seek early input on the Project and to explore ways to maximize economic benefits

to the local communities.

Summary of Results of the 65,000 Tons Per Day PFS

OPERATING METRICS 2021 PFS

Mill Throughput 65,000 tons/day

Head Grade – Year 1-5(1) 0.79 g/tonne

Head Grade – LOM(1) 0.65 g/tonne

Gold Recovery – LOM 71.4 %

Mine Life 21 years

Total Ounces Produced 6,430,178 Troy ounces

Average Annual Production – Year 1-5 388,600 Troy ounces

Average Annual Production – LOM 306,200 Troy ounces

Total Ore Processed 474 Million tons

Total Waste(2) 547 Million tons

Annual Mining Rate 52 Million tons

Waste Rock to Mill Ore (ton) Ratio – LOM during production 0.98:1 Waste to Ore

Waste Rock to Mill Ore (ton) Ratio – LOM 1.15:1 Waste to Ore

Low Grade Stockpile – Total Placed/Maximum Size 105/88 Million tons

(1) Diluted grade

(2) Includes 84 million tons pre-production

International Tower Hill Mines Ltd. - 4 - November 4, 2021

NR21-06 Continued

FINANCIAL METRICS 2021 PFS US$

CAPEX – Initial 1.93 $Billion

CAPEX – Sustaining 658 $Million

Reclamation & Closure 322 $Million

OPEX – Mining 2.05 $/ton mined

OPEX – Processing 7.72 $/ton ore

OPEX – General &Administrative (G&A) 1.35 $/ton ore

OPEX - Operating Cost – Year 1-5 887 $/Ounce

OPEX - Operating Cost – LOM 1,068 $/Ounce

All-In Sustaining Cost of Production – Year 1-5 1,038 $/Ounce

All-In Sustaining Cost of Production – LOM 1,171 $/Ounce

Gold Price Sensitivity Analysis

The following table shows the average annual free cash flow and EBIDTA generated by the Project at various

gold prices.

(US$M) FREE CASH FLOW EBIDTA

Gold Price

($/Oz)

Average Annual

(Year 1-5)

Average Annual

(LOM)

Average Annual

(Year 1-5)

Average Annual

(LOM)

$1,500 $159 $108 $229 $142

$1,680 (PFS

Base Case $225 $154 $296 $197

$1,800 $269 $184 $342 $234

$2,000 $332 $232 $417 $295

$2,500 $482 $349 $605 $449

The following table shows the after-tax economics at various gold prices.

Gold Price ($/Oz) AFTER TAX

NPV 0% ($M)

AFTER TAX

NPV 5% ($M) IRR (%) Payback (Years)

$1,500 $202 ($512) 1.00% 16.2

$1,680 (PFS Base

Case) $1,137 $45 5.30% 10.4

$1,800 $1,741 $400 7.70% 8.2

$2,000 $2,729 $975 11.20% 6.3

$2,500 $5,102 $2,351 18.50% 3.9

International Tower Hill Mines Ltd. - 5 - November 4, 2021

NR21-06 Continued

Capital Costs

Key capital expenditures for initial and sustaining capital requirements are identified in the following table.

US$ Million

Description Initial Sustaining

Process Facilities $433

Infrastructure Facilities 459 $514

Power Supply 87

Mine Equipment 200 139

Mine Development 230

Owners Costs 296 5

Contingency 220

Total $1,925 $658

Rounding of some figures may lead to minor discrepancies in totals.

All-in Sustaining Costs

The table below highlights the all-in sustaining costs and the all-in cost over the life of the Project:

Year 1-5 LOM

US$/Ounce US$ Million US$/Ounce US$ Million

Operating Costs $887 $1,724 $1,068 $6,870

Sustaining Capital Expenditures 151 292 102 658

All-In Sustaining Costs(1) $1,038 $2,016 $1,171 $7,529

Capital Expenditures (2) (3) 0 0 299 1,925

Funding of Reclamation Trust Fund (4) 30 58 42 268

All-In Costs(1) $1,068 $2,075 $1,512 $9,722

Rounding of some figures may lead to minor discrepancies in totals.

(1) All-In Sustaining Costs and All-In-Costs are non-IFRS

measures. See reference to “Non-IFRS Measures” below.

(2) Includes initial capital expenditures only.

(3) Excludes US$40 million of recoverable initial stores

inventory.

(4) Total US$322 million estimated costs.

Annual Gold Production

The chart below highlights the anticipated production schedule. Total life-of-mine production is anticipated to be

6,430,178 ounces. Mill feed will consist of reclaimed ore from the low-grade stockpile during Years 18 through

21.

International Tower Hill Mines Ltd. - 6 - November 4, 2021

NR21-06 Continued

Year Mill Feed Grade (g/tonne) Ounces Produced (000)

1 0.76 321

2 0.69 388

3 0.93 482

4 0.93 437

5 0.61 314

6 0.61 328

7 0.64 340

8 0.64 329

9 0.69 357

10 0.58 306

11 0.61 296

12 0.72 336

13 0.77 339

14 0.77 322

15 0.71 308

16 0.73 316

17 0.65 293

18 0.36 188

19 0.36 188

20 0.36 188

21 0.37 54

LOM 0.65 6,430

Rounding of some figures may lead to minor discrepancies in totals.

Project Mineral Reserves

The table below presents the Mineral Reserve estimate for the Project (effective as of October 22, 2021). These

Proven and Probable Mineral Reserves formed the basis of the ec onomic evaluation of the Project and are

based on a gold price of US$1,680 per ounce. The economic assum ptions and parameters used for the

calculation of reserves are the same as those used for the PFS financial model. Note that tonnages presented

are in the metric system.

Livengood Gold Project Mineral Reserve Estimate

(1) Mineral Reserves are reported using the 2014 CIM Definition Standards and are estimated in accordance with 2019 CIM Best

Practices Guidelines.

(2) Mineral Reserves are estimated using a gold price of US$1,680 per ounce, and consider a 3% royalty, 1.80/oz for smelting,

refining, and transportation costs, and a gold payable of 99.9%

(3) Metallurgical recovery curves were developed for each rock type, with the Mineral Reserves having the following tonnage

weighted averages; 83.3%, for Rocktype 4, 79.8% for Rocktype 5, 73.5% for Rocktype 6, 66.4% for Rocktype 7, 58.7% for

Rocktype 8 and 57.1% for Rocktype 9, including 22% for massive stibnite mineralization.

Classification Tonnes (Mt) Au (g/tonne) Contained Au

(000’s)

Proven 411.5 0.64 8,492

Probable 18.5 0.86 512

Total P & P 430.1 0.65 9,004

International Tower Hill Mines Ltd. - 7 - November 4, 2021

NR21-06 Continued

(4) As a result of the complex metallurgical recovery equations, it is difficult to determine specific cut-off grades. The following

presents the lowest gold grades for each rocktype that are processed in the life of mine plan; 0.26 g/t for Rocktype 4, 0.28 g/t

for Rocktype 5, 0.31 g/t for Rocktype 6, 0.31 g/t for Rocktype 7 and 0.42 g/t for Rocktype 8 and 0.42 g/t for Rocktype 9.

(5) The strip ratio for the open pit is 1.2 to 1.

(6) The Mineral Reserves are inclusive of mining dilution and ore loss.

(7) The reference point for the Mineral Reserves is the primary crusher.

(8) Totals may not add due to rounding.

(9) The foregoing mineral reserves are based upon and are included within the current mineral resource estimate for the Project.

Project Mineral Resources

The mineral resource estimates set forth in the PFS (“2021 MRE” ) have been prepared by Resource

Development Associates Inc. (“RDA”). Compared to the mineral resource estimates in the 2017 Report, the

2021 MRE included spatial modelli ng of the occurrence of antimo ny throughout the deposit as well as

modelling of the locations of massive stibnite veins within the deposit. These details add valuable contributions

to the reasonable prospects of eventual economic extraction of gold for the Project. Gold mineralization has

been interpolated into 10 x 10 x 10-meter blocks using inverse distance cubed (ID3) estimation techniques,

believed to more conservatively support future production sched ules as compared to the 2017 Report, which

was based on Multiple Indicator Kriging of 15 x 15 x 10-meter b locks parceled into 7.5 x 7.5 x 10-meter

selective mining units.

Table 1 Mineral Resource Estimate – Open Pit Constrained – Economic Parameters at Gold Selling Price of

US$1,650 per Troy Ounce. Resources Estimated at Variable Au Cutoff Grades – as described in Table 2

(Qualified Person: Scott Wilson CPG; Effective August 20, 2021)

Classification Tonnes

(Mt) Au (g/t)

Contained

Au

(000’s)

Measured 646.0 0.60 12,482

Indicated 58.5 0.61 1,142

Total M & I 704.5 0.60 13,624

Inferred 16.0 0.40 207

Mineral resources for the Project were determined based upon a combination of 776 reverse circulation and

diamond drillholes comprising 147,658 assays of which 125,450 a ssays measured detectable Au

mineralization. High grade Au outliers were capped prior to compositing. Assays were composited to nominal

ten-meter lengths, yielding 20,806 individual samples which wer e used for the estimation of mineralization.

Mineralization was determined using inverse distance cubed esti mation techniques, adhering to geological

constraints throughout the mineral deposit.

In order to define the quantities of Au with “reasonable prospe cts for economic extraction” by open pit

methods, RDA determined pit cons training limits using the Lerch s-Grossman© economic algorithm which

constructs lists of related bloc ks that should or should not be mined. The final list de fines a surface pit shell

that has the highest possible total value, while honoring the r equired surface mine slope and economic

parameters. Mineral resources were determined at a gold selling price of US$1,650.

The parameters listed in Table 2 define a realistic basis to es timate the mineral resources for the Project and

are based on the extensive scientific, metallurgical and engine ering based analyses that have been completed

by Tower Hill Mines since 2006. Mineral resources for the Project have been limited to mineralized material

that occurs within the pit shells and which could be scheduled to be processed based on the defined cut-off

International Tower Hill Mines Ltd. - 8 - November 4, 2021

NR21-06 Continued

grades. All other material within the constraining pit, which w as not classified according to CIM Definition

Standards, was characterized as non-mineralized material.

Table 2 Pit Constraining Parameters

Parameter Unit Rock

Type 4

Rock

Type

5

Rock

Type

6

Rock

Type

7

Rock

Type

8

Rock

Type

9

Mining Cost

Unprocessed

Rock

US$/tonne 1.76 1.74 1.74 1.68 1.76 1.76

Processing

Cost

US$/

process

tonne

9.27 9.15 9.17 9.50 9.71 9.71

G & A US$/process

tonne 1.55 1.55 1.55 1.55 1.55 1.55

Au Recovery Avg % 1 84 80 71 67 55 56

R o y a l t y % 3 3 3 3 3 3

Au Selling

Price US$/oz 1,650 1,650 1,650 1,650 1,650 1,650

Au Cut-Off g/tonne 0.21 0.20 0.25 0.25 0.33 0.33

Overall Slope

Angle Degrees 45 45 45 45 45 45

1 Average % Au Recovery includes massive stibnite at 22% recovery

Grade and Tonnage Sensitivity to Cutoff Grade

Mineral resources at Livengood are sensitive to the selection o f the reporting cutoff grade. To illustrate this

sensitivity, the block model quantities and grade estimates within the constraining pit are presented in Table 3

at linear increases in the cutoff grades for measured, indicate d and inferred mineral resources at Livengood.

The same results are presented graphically in Figure 1. Mineral ization is constrained to the pit using the

parameters in Table 2. The numbers presented in Table 3 should not be misconstrued with a mineral resource

statement. The figures are only presented to show the sensitiv ity of block model estimates to the selection of

a cutoff grade. Mineral resources are not mineral reserves and do not have demonstrated economic viability.

Table 3 Sensitivity of Mineral Resources to cutoff used. Effective Date: August 20, 2021.

QP Scott Wilson CPG

Measured Indicated Measured & Indicated Inferred

Cutoff

Au g/t

Tonnes

(000)

Grade

Au

g/t

Au

Oz.

(000)

Tonnes

(000)

Grade

Au

g/t

Au

Oz.

(000)

Tonnes

(000)

Grade

Au

g/t

Au

Oz.

(000)

Tonnes

(000)

Grade

Au

g/t

Au

Oz.

(000)

0.2 816,569 0.53 13,914 73,263 0.53 1,248 889,832 0.53 15,162 20,42 3 0.37 243

0.3 626,843 0.61 12,293 55,069 0.63 1,115 681,912 0.61 13,409 13,35 9 0.43 185

0.4 464,710 0.71 10,608 37,347 0.76 913 502,057 0.71 11,520 6,017 0 .52 101

0.5 332,891 0.81 8,669 25,437 0.91 744 358,328 0.82 9,413 2,142 0.6 5 45

0.6 234,524 0.92 6,937 17,976 1.06 613 252,500 0.93 7,549 1,079 0.7 5 26

0.7 164,938 1.03 5,462 13,645 1.19 522 178,583 1.04 5,984 614 0.84 17

0.8 117,098 1.15 4,329 10,648 1.31 448 127,746 1.16 4,778 335 0.92 10

0.9 83,825 1.26 3,396 8,372 1.44 388 92,197 1.28 3,783 180 0.98 6

1.0 61,474 1.38 2,727 6,479 1.58 329 67,953 1.40 3,057 59 1.04 2

Figure 1 Sensitivity of Mineral Resources to cutoff used. Effective Date: August 20, 2021. QP Scott Wilson CPG