PolyMet Closes IRRRB Loan

HOYT LAKES, MINNESOTA -- (Marketwire) -- 06/30/11 -- PolyMet Mining Corp. (TSX: POM)(NYSE Amex: PLM) ('PolyMet' or the 'Company') today reported that:

--  It has closed the previously-announced $4 million loan from Iron Range
    Resources & Rehabilitation Board ('IRRRB')
--  It has exercised its option to acquire two tracts of land totaling
    approximately 5,375 acres of forests, wetlands, and lakes with high
    recreational value that are included as part of the proposed land
    exchange with the U.S. Forest Service

$4 million Loan & Land Acquisition

On April 15, 2011 the IRRRB reapproved a secured loan to PolyMet's wholly owned subsidiary, Poly Met Mining, Inc., of $4 million. The loan, which was approved by the Governor of the State of Minnesota on May 3, 2011, was originally approved by the IRRRB on December 16, 2010 but did not proceed until a legal challenge was withdrawn. State legislation clarified that the IRRRB is a regional economic development agency with no regulatory oversight for permitting activities.

The loan is secured by the land being acquired, carries a fixed interest rate of 5% per annum, and will be repayable on June 30, 2016. PolyMet has issued warrants giving the IRRRB the right to purchase 400,000 shares of its common stock at US$2.50 per share at any time until the earlier of June 30, 2016 or one year after permits are received.

About PolyMet

PolyMet Mining Corp. (www.polymetmining.com) is a publicly-traded mine development company that controls 100% of the NorthMet copper-nickel-precious metals ore body through a long-term lease and owns 100% of the Erie Plant, a large processing facility located approximately six miles from the ore body in the established mining district of the Mesabi Range in northeastern Minnesota. PolyMet Mining Corp. has completed its Definitive Feasibility Study and is seeking environmental and operating permits to enable it to commence production. The NorthMet project is expected to require approximately one-and-a-quarter million hours of construction labor and create approximately 360 long-term jobs, a level of activity that will have a significant multiplier effect in the local economy.

POLYMET MINING CORP.

Joe Scipioni, CEO

This news release contains certain forward-looking statements concerning anticipated developments in 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 proceeds and closing of the registered direct offering, exploration results and budgets, reserve estimates, mineral resource estimates, work programs, capital expenditures, actions by government authorities, including changes in government regulation, the market price of natural resources, costs, or other statements that are not a statement of fact. Forward-looking statements address future events and conditions and therefore involve inherent risks and uncertainties. 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. 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, 2011 and in our other filings with Canadian securities authorities and the Securities and Exchange Commission, including our Report on Form 6-K providing information with respect to our operations for the year ended January 31, 2011 for a discussion of some of the risk factors and other considerations underlying forward-looking statements.

The TSX has not reviewed and does not accept responsibility for the adequacy or accuracy of this release.

Contacts:

PolyMet Mining Corp. - Corporate

Douglas Newby

Chief Financial Officer

1 (212) 867-1834
dnewby@polymetmining.com


PolyMet Mining Corp. - Media

LaTisha Gietzen

VP Public, Gov't & Environmental Affairs

1 (218) 225-4417
lgietzen@polymetmining.com


PolyMet Mining Corp. - Investors

Crystal Agresti

1 (845) 742-8153
cagresti@polymetmining.com


PolyMet Mining Corp. - Investors

Alex Macdougall

1 (226) 663-3000
amacdougall@polymetmining.com
www.polymetmining.com