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Erdene Intersects 33.5 G/T GOLD over 8 Metres Near Surface at Dark Horse Mane Discovery

Drill Results

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ERDENE INTERSECTS 33.5 G/T GOLD OVER 8 METRES NEAR

SURFACE AT DARK HORSE MANE DISCOVERY

Press Release

Halifax, Nova Scotia

2021.11.17

Erdene Resource Development Corporation ( TSX: ERD | MSE: ERDN) (“Erdene” or the

“Company”) is pleased to announce results from the follow-up drill program at Dark Horse

Mane, 2.4 kilometres north of the construction-ready Bayan Khundii Gold Pro ject. This

drilling program confirmed a high-grade oxide gold zone starting at surface, open at depth

and along strike.

Highlights

• Intersected high-grade gold, in near surface oxide zone in southern Dark Horse Mane:

o ADD-146: 17 metres of 16.7 g/t gold beginning 15 metres downhole

o Includes 8 metres of 33.5 g/t gold

o ADD-137: 24.5 metres of 9.4 g/t gold beginning 1.5 metres downhole

o Includes 13.5 metres of 16.1 g/t gold

o ADD-138: 25 metres of 6.1 g/t gold beginning 18 metres downhole

o Includes 8 metres of 17.1 g/t gold

o ADD-136: 30 metres of 5.6 g/t gold beginning 6 metres downhole

o Includes 13 metres of 11.6 g/t gold

• High-grade oxide ore is expected to be processed by the Bayan Khundii plant and

should improve the scale and economics of the Bayan Khundii Gold Project

• Drilling in northern Dark Horse Mane established a large-scale prospect at depth

o Extension of hole AAD-92 returned multiple gold bearing zones within a 100-

metre-thick alteration zone, and ended in over 1 g/t gold, 150 metres downhole

• Ulaan Gold prospect drilling commencing this week and follow-up Dark Horse drilling

to commence in late Q4 2021

o Follow-up exploration will test targets along strike and at depth, as well as other

potential oxide zones on the Khundii and Ulaan licenses

Quotes from the Company:

“Today’s results demonstrate the near-term value Dark Horse can add to the Bayan

Khundii development , as well as the potential scale of the Khundii-Ulaan alteration

system,” said Peter Akerley, Erdene’s President and CEO . “These near -surface high-

grade oxide gold zones have the potential to meaningfully elevate the Bayan Khundii Gold

Project’s economics, while also demonstrating the potential for near -surface targets

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throughout our license holdings. The Dark Horse Gold Zone has been traced over 1.5

kilometres and presents significant expansion potential in all directions.”

“Furthermore, these results strengthen our conviction that the greater Khundii -Ulaan

alteration trend, including Dark Horse, the Bayan Khundii Deposit, and the recent Ulaan

discovery, are part of the same gold-bearing hydrothermal system . This system shows

the potential to host a multimillion -ounce gold deposit ,” continued Mr. Akerley.

“Exploration drilling is currently underway at our Ulaan target, 3 kilometres south of Dark

Horse Mane, and follow-up drilling is planned to continue at Dark Horse later in Q4.”

Summary of Drill Results

The drilling results reported herein are from the Dark Horse Mane prospect. The primary

objective of the recent drilling program was confirming grade and continuity of near-

surface oxide gold mineralization . A total of 32 new holes and two hole-extensions,

totaling 2,286 metres were completed. While three holes were drilled to between 109 to

318 metres vertical depth, most drill holes (31) were between 21 and 61 metres vertical

depth.

Results from drilling to date confirm a 1.5-kilometre trend of alteration and gold

mineralization within the Dark Horse Mane target area that remains open along strike to

the north and south. Continuity of near-surface, oxide, supergene gold mineralization has

been defined over a strike length of approximately 350 metres in the south and over 500

metres in the north.

Table 1 below summarizes results from the Dark Horse Mane (south) prospect, which is

typified by oxide mineralization starting at surface with evidence of supergene enrichment.

Table 2 provides results for Dark Horse Mane (north) where near surface oxide

mineralization is prevalent, albeit lower grade than at Dark Horse Mane south.

Table 1: Dark Horse Mane (South) Q4 2021 Drilling Highlights (Intervals averaging

over 0.30 g/t gold)

Hole From To Interval (1) g/t Au

AAD-134 164 165 1 0.58

AAD-135 14 24 10 0.31

AAD-136 6 36 30 5.59

Incl 10 23 13 11.63

Incl 16 20 4(2) 24.06

AAD-137 1.5 26 24.5 9.37

Incl 4.5 18 13.5 16.08

Incl 4.5 9 4.5(2) 17.23

Incl 12 16 4(2) 27.68

AAD-138 18 43 25 6.06

Incl 26 34 8 17.07

Incl 25 26 1 29.94

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Hole From To Interval (1) g/t Au

Incl 31 34 3(2) 31.01

AAD-139 1.5 9 7.5 0.38

And 20 21 1 0.44

AAD-140 18 19 1 0.50

And 42 51 9 0.60

AAD-141 1.9 37 35.1 1.31

Incl 10 21 11 3.35

Incl 11 12 1 14.72

AAD-142 22 23 1 0.44

And 24 25 1 0.37

And 28 32 4 0.34

And 35 36 1 0.51

And 39 40 1 0.32

And 71 72 1 0.35

AAD-143 5 19 14 5.44

Incl 12 15 3(2) 18.74

AAD-144 13 49 36 1.25

AAD-145 41 43 2 2.71

And 70 72 2 0.74

AAD-146 6 7 1 1.11

And 15 32 17 16.65

Incl 22 30 8 33.52

Incl 22 25 3(2) 65.00

Incl 27 30 3(2) 21.12

AAD-148 5 28 23 1.15

AAD-149 26 42 16 1.34

AAD-151 21 33 12 0.53

And 38 58 20 0.41

AAD-152 14 26 12 0.56

AAD-153 23 26 3 0.48

AAD-154 37 38 1 0.37

1. Reported intervals in this release are downhole apparent widths. Continued exploration is required to confirm anisotropy of

mineralization and true thicknesses

2. For each of these intervals, all samples (1 to 1.5 metres) returned assays of greater than 10 g/t gold, ranging from 11.21 to

89.26 g/t gold

3. End of hole

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Table 2: Dark Horse Mane ( North) Q4 2021 Drilling Highlights (Intervals averaging

over 0.30 g/t gold)

Hole From To Interval (1) g/t Au

AAD-92X 53 85 32 0.51

And 96 98 2 0.50

And 108 120 12 0.50

And 132 150(3) 18 0.72

AAD-156 41 50 9 0.76

AAD-157 7 24 17 0.40

And 39 40(3) 1 0.65

AAD-158 16 26 10 0.76

AAD-159 7 9 2 0.32

AAD-160 15 16 1 0.59

And 20 24 4 0.36

And 32 40 8 0.99

AAD-161 8 10 2 0.60

And 36 40(3) 4 0.45

AAD-162 11 21 10 0.69

And 25 27 2 0.72

AAD-163 21 24 3 0.53

And 40 48 8 0.93

AAD-164 32 41 9 0.48

AAD-165 20 21 1 0.33

And 29 30 1 0.46

AAD-166 56 70 14 1.10

AAD-167 13 15 2 0.48

1. Reported intervals in this release are downhole apparent widths. Continued exploration is required to confirm anisotropy of

mineralization and true thicknesses

2. For each of these intervals, all samples (1 -1.5 metres) returned assays of greater than 10 g/t gold, ranging from 11.21 to

89.26 g/t gold

3. End of hole

The 350-metre southern portion of Dark Horse Mane oxide zone includes a very high-

grade gold zone, traced over 200 metre s, which was the focal point of recent drill ing.

Depth of oxidation reaches more than 100 metres locally, related to deep weathering

along structures. In this high-grade central zone, the main mineralized body begins within

one metre of surface, and ranges from 10 to 40 metres in thickness. The trend of the gold

mineralization at Dark Horse Mane is interpreted to be plunging to the north as shown in

the attached Sections 1 and 2. One previously reported hole, AAD-57, was drilled north

of the very high -grade zone and returned multiple two-metre samples grading greater

than 4 g/t gold , at a vertical depth of app roximately 200 met res. These results

demonstrate the potential for additional gold mineralization at depth , down plunge from

the mineralization identified near surface . As well, t his down-plunge mineralization may

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extend to depth under the northern portion of Dark Horse Mane prospect, an area that

has not been tested to date.

Two deeper holes were drilled in Dark Horse Mane south. The extension of AAD-68

intersected a major fault structure characterized by quartz tourmaline metasomatize d

zones with intense tectonic breccia and high -density calcite stockwork veining and

breccia. Gold values were low to locally anomalous, however, copper grades increase at

depth with the hole ending in anomalous 98th percentile copper grades (greater than 700

ppm). AAD-134 was drilled to a vertical depth of 2 10 metres and intersected zones of

anomalous gold and copper in phy llic altered volcanics throughout the hole , supporting

continuity of the alteration and mineralized zone.

In the northern portion of Dark Horse Mane , 12 new holes intersected low to moderate

oxide gold grades, with evidence of bifurcation or parallel gold zones (example AAD-166).

One of the three deeper holes completed in this program tested the north zone over a

total extended drill length of 150 metres (AAD-92) and successfully intersected multiple

zones of gold bearing, sugary quartz -hematite veins within phyllic altered volcanic units

of increasing alteration intensity and grade down hole ending in 1 g/t gold material. AAD-

92 is located adjacent to AAD -61 which returned 130 meters of 0.5 g/t gold (previously

reported April 22, 2021). These results present a very strong, untested target at depth in

the central area of the northern portion of Dark Horse Mane (see Section 3). Previous

results from Dark Horse Mane (north) returned high-grade intersections, of up to 16.2 g/t

gold over 1 metre, at approximately 100 metres vertical depth (AAD-51), further

confirming the potential for high-grade gold mineralization at depth.

The Company’s most recent geological modelling has identi fied multiple drill targets

designed to assess the mineral potential of this exciting discovery. Compilation and

interpretation work continues to define a larger-scale drilling program for Dark Horse and

throughout the broader target area.

All samples have been assayed at SGS Laboratory in Ulaanbaatar, Mongolia. In addition

to internal checks by SGS Laboratory, the Company incorporates a QA/QC sample

protocol utilizing prepared standards and blanks as well as field and lab duplicates. All

samples undergo standard fire assay analysis for gold and ICP-OES (Inductively Coupled

Plasma Optical Emission Spectroscopy) analysis for 33 additional elements. For samples

that initially return a gold grade greater than 5 g/t, additional screen-metallic gold analysis

is carried out which provides a weighted average g old grade from fire assay analysis of

the entire +75 micron fraction and three 30-gram samples of the -75 micron fraction from

a 500 gram sample. Screen metallic grades are all reported.

Moving Forward

Follow-up d rilling at Dark Horse will commence later in Q4 , following drilling at Ulaan ,

where continuity and expansion of the new high-grade gold discovery (see press release)

is underway. Dark Horse drilling will include further shallow testing of the 2.4 kilometre

structure between Bayan Khundii and Dark Horse South , as well as the extension of the

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zone to the north. Selective testing of targets at moderate depths (200 to 300 metres) is

also planned.

The presence of gold-bearing oxide zones indicates that the level of erosion, hydrological

and atmospheric conditions within the Khundii-Ulaan alteration footprint are conducive to

seep oxidation and supergene enrichment gold mineralization. Evidence of these oxidized

zones is generally absent at surface as they correspond to the location of drainages that

mask the underlying material, albeit in some cases by little more than a metre. In addition,

reconnaissance drilling has typically targeted 50 metre plus vertical depth whereas this is

below the average depth of the highest grade gold in oxidized zones. The results from

Dark Horse Mane drilling demonstrate the potential for substantial, near-surface, oxide

gold zones, opening up multiple new targets across our license areas that will be followed

up in 2022. Erdene is planning to complete oxide-zone targeting over the broader Khundii

and Ulaan license using high density geochemical sample surveying and near surface

auger drilling to test subsurface regolith and undercover sub crop. Erdene is also

completing high resolution spectral remote sensing targeting surficial iron -oxide

signatures.

Dark Horse Overview

Erdene discovered Dark Horse Mane, 2.4 km north of the Bayan Khundii deposit , when

initial drilling, reported in early 2021, returned 5.97 g/t gold over 45 metres, beginning 10

metres downhole, including 8 metres of 27.1 g/t gold (AAD-58). This discovery

established Dark Horse as the most significant area of gold mineralization in Erdene’s

Khundii Gold District since the discovery of the Bayan Khundii gold deposit. To date the

Company has completed 14,681 metres of drilling in 128 holes at the greater Dark Horse

prospect, covering an area approximately 4.6 kilometres ( east-west) by 2.6 kilometres

(north-south). Drill hole vertical depths range from 21 to 318 metres and average only 87

metres.

The Dark Horse Mane zone is related to a north-south trending, linear structural corridor

which intersects deep seated northeast trending transform faults, believed to be a conduit

for primary mineralizing fluids . Gold mineralization is hosted within strongly altered

tuffaceous and volcanoclastic rocks, cross-cut by quartz and quartz-hematite veins and

stockwork zones. Recent drilling at Dark Horse Mane has confirmed the existence of a

shallow oxide zone, beginning from surface, hosting supergene enriched gold values up

to 89. 3 g/t over 1 metre. The high -grade oxide body exhibits strong continuity along a

north-south strike. Limits of mineralization and oxidation remain untested along strike and

at depth.

Khundii-Ulaan Mineralized System

The Ulaan exploration license and adjoining Khundii mining license cover nearly 4,000

hectares of the Khundii-Ulaan hydrothermal alteration zone , which extends from Ulaan

over 10 kilometres to the northeast. This alteration trend has a central zone of intense

secondary silica with a peripheral halo of sericite alteration, and an outer zone of white

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mica and sericite, which hosts the Bayan Khundii gold deposit. This northeast trending

alteration area, which incorporates the Ulaan, Bayan Khundii , Dark Horse and other

mineralized targets in the area, is associated with a regional structural dilational jog and

associated major volcano-plutonic centre, along a northeast trending transform fault. The

various styles of alteration and mineralization within the Khundii-Ulaan target area are

consistent with a fertile magmatic island arc, with evidence for possible arc migration, and

overlapping or telescoped mineralization along major structures.

The Khundii-Ulaan hydrothermal alteration is characterized by pervasive argillic, phyllic

and silica alteration signatures centered within Erdene’s Ulaan exploration license and

extending onto Erdene’s Khundii mining license for over 10 kilometres. The Khundii-Ulaan

alteration footprint remains largely under explored with numerous gold occurrences and

geochemical and/or geophysical anomalies that warrant future testing.

Exploration results to date suggest the greater Khundii-Ulaan alteration zone and known

gold occurrences are part of the same , large, gold-bearing hydrothermal system which

remains largely under-explored. Gold mineralization identified to date is hosted within an

expansive, white mica and silica altered tuffaceous sequence exposed around the

periphery of the Khundii-Ulaan hydrothermal alteration system. Quartz vein textures and

clay alteration compositions indicate a large-scale epithermal type of gold mineralizing

environment existed within the Khundii-Ulaan system with the tuffaceous lithologies

acting as preferred hosts for gold mineralization . Exploration planning is currently

underway to test multiple high -priority geological, geochemical and geophysical targets

across the Khundii-Ulaan target area.

Khundii Gold District

Erdene’s deposits are in the Edren Terrane, within the Central Asian Orogenic Belt, host

to some of the world’s largest gold and copper-gold deposits. The Company has been the

leader in exploration in southwest Mongolia over the past decade and is responsible for

the discovery of the Khund ii Gold District comprised of multiple high -grade gold and

gold/base metal prospects, one of which is currently being developed, the 100%-owned

Bayan Khundii Gold Project, and another which is being considered for development, the

100%-owned Altan Nar Project. Together, these deposits comprise the Khundii Gold

Project.

The Bayan Khundii Gold Resource1 includes 585,100 ounces of 2.19 g/t gold Measured

and Indicated (“M&I ”)2 and 35,900 ounces of Inferred resources at 2.18 g/t gold. Within

the M&I resource, a Proven and Probable open-pit reserve totals 409,000 ounces at 3.7

g/t gold3 (press release here), providing significant potential for reserves growth with the

development of the remaining M&I and Inferred resources1.

1 For details of the Mineral Resources see Erdene’s Q2/2021 results press release, dated August 16, 2021, and the

Company’s Q2 2021 MD&A, available on the Company’s website or SEDAR.

2 M&I: 232,700 ounces of 2.39 g/t gold Measured, and 352,400 ounces of 2.08 g/t gold Indicated

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In July 2020, Erdene announced the results of an independent Feasibility Study for the

Bayan Khundii Gold Project (press release here). The Feasibility Study results include an

after-tax Net Present Value at a 5% discount rate and a US$1,400/oz gold price of

US$100 million and Internal Rate of Return (“IRR”) of 42%. The Feasibility Study

envisions an open -pit mine at Bayan Khundii, prod ucing an average of 63,500 oz gold

per year, for seven years, at a head grade of 3.71 g/t gold, utilizing a conventional carbon

in pulp processing plant. Production is expected to commence in 202 3 based on the

current project schedule.

Erdene Resource Development Corp. is a Canada-based resource company focused on

the acquisition, exploration, and development of precious and base metals in

underexplored and highly prospective Mongolia. The Company has interests in three

mining licenses and two exploration licenses in Southwest Mongolia, where exploration

success has led to the discovery and definition of the Khundii Gold District. Erdene

Resource Development Corp. is listed on the Toronto and the Mongolian stock exchanges.

Further information is available at www.erdene.com. Important information may be

disseminated exclusively via the website; investors should consult the site to access this

information.

Qualified Person and Sample Protocol

Peter Dalton, P.Geo. (Nova Scotia), Senior Geologist for Erdene, is the Qualified Person

as that term is defined in National Instrument 43-101 and has reviewed and approved the

technical information contained in this news release. All samples have been assayed at

SGS Laboratory in Ulaanbaatar, Mongolia. In addition to internal checks by SGS

Laboratory, the Company incorporates a QA/QC sample protocol utilizing prepared

standards and blanks. All samples undergo standard fire assay analysis for gold and ICP-

OES (Inductively Coupled Pl asma Optical Emission Spectroscopy) analysis for 33

additional elements. For samples that initially return a grade greater than 5 g/t gold,

additional screen-metallic gold analysis is carried out which provides a weighted average

gold grade from fire assay analysis of the entire +75 micron fraction and three 30 -gram

samples of the -75 micron fraction from a 500 gram sample.

Erdene’s drill core sampling protocol consisted of collection of samples over 1 or 2 metre

intervals (depending on the lithology and style of mineralization) over the entire length of

the drill hole, excluding minor post -mineral lithologies and un -mineralized granitoids.

Sample intervals were based on meterage, not geological controls, or mineralization. All

drill core was cut in half with a diamond saw, with half of the core placed in sample bags

and the remaining half securely retained in core boxes at Erdene’s Bayan Khundii

exploration camp. All samples were organized into batches of 30 including a commercially

prepared standard, blank and either a field duplicate, consisting of two quarter -core

3 P&P: 165,000 ounces of 4.4 g/t gold Proven and 256,000 ounces of 3.4 g/t gold Probable; For details of the Mineral

Reserves see Khundii Gold Project NI 43 -101 Technical Report, Tetra Tech December 4, 2019, available on the

Company’s website or SEDAR