Minnesota Commitment | Global Opportunity

March 2016

Cautionary StatementThis presentation contains certain forward-looking statements concerning anticipated developments in PolyMet Mining Corp. (“PolyMet”)’s operations in the future. Forward-looking statements are frequently, but not always, identified by words such as “expects,” “anticipates,” “believes,” “intends,” “estimates,” “potential,” “possible,” “projects,” “plans,” and similar expressions, or statements that events, conditions or results “will,” “may,” “could,” or “should” occur or be achieved or their negatives or other comparable words. These forward-looking statements may include statements regarding our beliefs related to the expected project timelines, exploration results and budgets, reserve estimates, mineral resource estimates, continued relationships with current strategic partners, work programs, capital costs and expenditures, actions by government authorities, including changes in government regulation, the market price of natural resources, estimated production rates, costs, ability to receive environmental and operating permits, construction costs and hours created, job creation and other economic benefits, or other statements that are not a statement of fact.

Forward-looking statements address future events and conditions and therefore involve inherent known and unknown risks and uncertainties. These risks, uncertainties and other factors include, but are not limited to, adverse general economic conditions, operating hazards, inherent uncertainties in interpreting engineering and geologic data, fluctuations in commodity prices and prices for operational services, government regulation and foreign political risks, fluctuations in the exchange rate between Canadian and US dollars and other currencies, as well as other risks commonly associated with the industry. Actual results may differ materially from those in the forward-looking statements due to risks facing PolyMet or due to actual facts differing from the assumptions underlying its predictions.

In connection with the forward-looking information contained in this presentation, PolyMet has made numerous assumptions, regarding, among other things: the geological, metallurgical, engineering, financial and economic advice that PolyMet has received is reliable, and is based upon practices and methodologies which are consistent with industry standards. While PolyMet considers these assumptions to be reasonable, these assumptions are inherently subject to significant uncertainties and contingencies.

PolyMet’s forward-looking statements are based on the beliefs, expectations and opinions of management on the date the statements are made, and PolyMet does not assume any obligation to update forward-looking statements if circumstances or management’s beliefs, expectations and opinions should change.

Specific reference is made to PolyMet’s most recent Annual Report on Form 20-F for the fiscal year ended January 31, 2015 and in our other filings with Canadian securities authorities and the U.S. Securities and Exchange Commission, including our Report on Form 6-K providing information with respect to our operations for the three months ended October 31, 2015 for a discussion of some of the risk factors and other considerations underlying forward-looking statements.

PolyMet’s financial statements have been prepared in accordance with International Financial Reporting Standards ("IFRS"). All amounts are in U.S. funds.

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A Minnesota Copper Growth Story

§ NorthMet Project:

- Measured & Indicated 694M tons @0.74% CuEq

- Mine Plan 224M tons @0.77% CuEq

§ EIS is complete – State of Minnesota has validated

§ Next steps include federal Records of Decision, permits and construction

§ Commercial production expected ~24 months after receiving permits

§ NorthMet cash flows remain attractive at current commodities prices

§ Continued support from Glencore – financial, commercial and technical

§ Construction financing is on-going

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The NorthMet Project

§ Established within the Duluth Complex, adjacent to the Mesabi Iron Range.

§ Final EIS is complete and validated.

§ PolyMet controls 100% of the NorthMet project.

§ MN is geopolitically stable and mining friendly.

§ Skilled mining community in place.

§ Experienced management team with a track record of permitting, building and operating responsible mining operations.

20 Year Operating Plan | 224M Tons32,000 Tons/Day Production Plan

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Existing tailing facility

Cliff NR –Northshore Mine

Waste Rock Storage

Existing Plant Site

Rail Line

North

EAST PIT

WEST PIT

6 miles

PolyMet – NorthMet Mine Operation

The NorthMet Project

§ Using existing Erie Plant and infrastructure located near the ore body and connected by existing rail.

§ Low cost for production of Cu makes this an attractive & competitive project.

§ PolyMet controls 100% of the mineral resource.

§ Offtake agreements in place with Glencore for all Cu | Ni concentrate production.

§ ~1,000 total jobs created in MN.

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Experienced Leadership

Jon Cherry, President, CEO, DirectorLeader in mining environmental policy and new mining projects, 20 years with Rio Tinto in the U.S.; 25 years experience in the industry

Brad Moore, VP Environmental & Gov. AffairsPermitting and regulatory expert, former senior Minnesota government official

Douglas Newby, Chief Financial OfficerMine finance expert, former Chairman/CEO of Western Goldfields (now New Gold) ~30 years experience

Andrew Ware, Chief GeologistExpert on the Duluth Complex and the mid-ContinentRift, broad experience in SE Asia and Mexico. 25 years with Rio Tinto

Jim Tieberg, Mine ManagerOver 20 years experience in mine operations, engineering, drilling/blasting & tailings basin construction.

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EPA RatingEPA EIS rating scale

LO:

Lack

of

Obj

ectio

ns

EC

: En

viro

nmen

tal

Con

cern

s

EO

: En

viro

nmen

tal

Obj

ectio

ns

EU

: En

viro

nmen

tally

Uns

atis

fact

ory

2009 EPA Rating

EC-2 *MN PolyMet’s NorthMet Project*MN Light Rail Project*MN St. Croix River Bridge

2014 EPA Rating

3

2

1

3

2

1

3

2

1

typically conservation& wilderness projects

**

* 2012 Mount Hope* 2012 Hollister Silver

* 2012 Rosemont Copper

EPA Comment On Final EIS

“Our extensive discussions with the co-lead and cooperating agencies have helped to resolve virtually all of our previous comments, and to review important questions about project

modeling.”

— EPA Office of Enforcement and Compliance Assurance, 08/05/2015

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Path To Permits

Final EIS2015

Records of Decision

State Permits

Federal Permits

Adequacy Decision

2016

✓ ConstructionSDEIS2013

Draft EIS2009

EIS Scoping

2005 ✓✓✓✓

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The NorthMet Resource

TonnageMillion ST

Tonnage Million MT

% CopperCu Equivalent

Million Pounds Cu Equivalent *

Mineral Resource **

MeasuredIndicated

M+I

203492694

184446630

0.79%0.72%0.74%

3,2047,052

Inferred 230 208 0.75% 3,446

Reserves 275 249 0.79% 4,340

* Metals converted to copper based on 2008 DFS update metals prices** $7.42/Net metal value cut-off – January 2013, 43-101 ($1.25/lb copper)20 Year Mine Plan subject to permit applications ($1.25/lb copper)

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Unit 4/5

Unit 6

Unit 1

Unit 7

Unit 2/3

Section 35400ME (Looking North East)

Pit wall

0.5 CuEq and Above

0.25 to 0.5 CuEq

World Class Copper District

§ Disseminated, Polymetallic Deposit § Low Strip (waste:ore) Ratio (1.4:1 life-of-mine), § Minimal Over-Burden§ Based on $1.25/Pound Copper / cut-off grade

NorthMet Ore Body

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Investment to date

Strategic Alliance With Glencore

§ Financial support $186M to date

§ Commercial offtake agreement in place

§ Technical support

Glencore Support

$ in

Mill

ions

$34.9M

$96M

$13M

Equity at $1.38/share weighted average

Glencore loan facility: $42M

Glencore convertible debt: $34M @ 1.29/share

$30M

Purchase of all 9.2 million shares previously owned by Cliffs Natural Resources

0

20

40

60

80

100

120

140

160

180

200

$42M

$96M

$13M

$34M

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Shareholder Data

Share & Balance Sheet Information

Share price (NYSE MKT: PLM) as of 3/2/16 US $1.13

Share price (TSX: POM) as of 3/2/16 C $1.51

Common shares outstanding 277.3M

Fully diluted shares:§ Float: 60.3%§ Glencore: 33.8%§ Management: 5.9%

332.5M

Market capitalization US $313M

*Cash and cash equivalents $9.3M

*Total debt $47.1

*Figures are as of the most recent financial statement

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Summary

§ 694M tons M+I @0.74% CuEq | Mine Plan 224M tons @0.77% CuEq

§ EIS Complete – next steps include permits and construction

§ Experienced management team with proven track record

§ NorthMet Project economics remain attractive

§ Construction financing is on-going

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