TSX Venture SYMBOL: NSM

September 20, 2007

FOR IMMEDIATE RELEASE

NEW PROPERTY ACQUISITION

Northern Star Mining Corp. (TSX.V-NSM) has signed an agreement to acquire the remaining 27.9% interest in the Piché-Harvey project, which is located between the Midway-Malartic gold project of Northern Star to the east and the Canadian Malartic gold project of Osisko Exploration to the west.

Northern Star originally acquired 72.1% of the Piché-Harvey project in March of 2007, and with the present acquisition now owns 100% of the project.

The Piché-Harvey gold project is located in the heart of the well known and prolific Malartic gold camp of the Abitibi Gold Belt, which has produced over 9 million ounces since 1935. The most important producers were the East Malartic Mine (88.71 tons Au) and the Malartic Goldfields Mine (52.95 tons Au) (ref. E. Lemieux, Cambior, report Piché project 1996).

The Piché-Harvey project consists of 37 mining claims comprising 584 hectares, and is located some 16 km west of the city of Val-d’Or, contiguous with Northern Star’s Midway Malartic project.

The Midway-Malartic project is the main advanced exploration project of the Company and contains the past producing Malartic Goldfields Mine (production 1939-1965, 52.95 tons Au) (ref. E. Lemieux, Cambior, Piché project report 1996). Preparations for a complete underground exploration project at the site of Malartic Goldfields shaft no. 1 (900 meters total depth) including detailed drilling and bulk sampling are currently underway. Geological information acquired has resulted in the planning and start up of a 30,000 meter drill program outside the immediate mine shaft area, on lateral and depth extensions of known gold bearing structures and on promising targets such as gold bearing porphyry systems in the Cadillac Break Deformation zone. Geological information tends to indicate that these porphyries may be eastern extensions of similar structures being explored and developed to the west by Osisko Exploration Ltd. (ref.).

Historical work on the Piché-Harvey project included diamond drilling by Malartic Goldfields Limited (1934-1972) (49 diamond drill holes for 9,000 meters). This original diamond drilling located 3 gold zones within porphyries in the southern part of the Cadillac Break Deformation zone.

North Zone : Gold intersections (widths along core axis) include 4.1 g/t Au over 3.9 m, 9.5 g/t Au over 1.5 m, 5.6 g/t Au over 2.8 m and 5.2 g/t Au over 2.1 m.

Contact Zone : Gold intersection includes 10.3 g/t Au over 1.0 m

South Zone : Gold intersections include 2.3 g/t Au over 5.4 m, 7.6 g/t Au over 6.3 m, 2.9 g/t over 8.0 m, 3.3 g/t Au over 4.2 m.

In 1980-1982, Soquem carried out 9 diamond drill holes (1,650m) and more recently in 2005, Cambior completed 4 additional drill holes (1,490 m). Both exploration programs confirmed the existence of these gold-bearing porphyries.

The north contact of the Cadillac Break Deformation Zone has also been explored in the past with sporadic widely spaced drill holes (over 100 m) which intersected favorable geology. The holes were all shallow, however, drilled less than 120 meters in depth. This north contact represents the western extension of the mining operations of Malartic Goldfields shaft no.2 (also part of the Midway-Malartic project of Northern Star). 5 of 11 drill holes intersected anomalous gold values (1.0 g/t Au over 1.0 m) to sub-economic gold values (4.6 g/t Au over 1.5 m) at shallow depths. No exploration has been carried out below 120 meters in depth along this 1.5 km of favorable geological horizon.

Exploration diamond drilling on the northern part of the property, outside the Cadillac Break Deformation Zone, also located the eastern extension of the Blake River Group. This geological formation is known, further to the west, for hosting the Agnico Eagle Laronde, Doyon and Bousquet mines in a geological environment favorable for gold mineralization. Two holes drilled 1.0 km apart on the Piché-Harvey project in the Blake River group returned 15.40 g/t Au over 1.5 m to the west and 4.7 g/t Au over 1.5 meters to the east.

The Company can acquire the remaining 27.9% of the project from the Succession Lloyd Harvey by issuing 350,000 common shares of the Company. The acquisition will be incorporated into the original agreement between Northern Star and Succession Lloyd Harvey. To complete payment of the acquisition of a 100% interest in the Piché-Harvey project, the Company must issue 750,000 shares and $50,000 in cash in the second quarter of 2008, and 750,000 shares and $50,000 in cash in the second quarter of 2009. Northern Star must also carry out 2 million dollars of exploration work prior to the third quarter of 2010.

The vendors retain a 3.0% N.S.R. royalty of which 1.5 percent may be purchased at any time by Northern Star for 1 million dollars.

Pursuant to TSX Venture Exchange finders fee policy, the maximum allowed in cash and/or shares will be payable to Geologica Inc., for the purchase of the 27.9% interest in this agreement.

The Company is very pleased with this acquisition as it adds significant exploration potential to the Midway-Malartic project. With the addition of the Piché-Harvey project, the Midway – Malartic project now consists of 116 claims covering 3,142 hectares (7,763 acres).

The transaction is subject to the approval of the regularity authorities.

Drilling has begun on the Piché-Harvey project, and continues using two diamond drill rigs on the Midway project as a whole. The Company expects to publish results shortly.

In other news, the Company announced on June 26 a motion to register a royalty agreement against certain mining claims belonging to Northern Star (press release June 26, 2007). The Company disputes this allegation.

The original motion was scheduled to be on July 10, 2007 but has been constantly delayed. The Company has not been informed of any motion date at this time.

Mr. Claude Larouche, geol., ing. (OIQ), acts as the qualified person for the Company and has reviewed the contents of this news release. The geological, and other information stated conforms to published reports available to the Company during their due diligence.

ON BEHALF OF THE BOARD

“Michel David”

Michel David President

FOR FURTHER INFORMATION PLEASE CONTACT: Northern Star Mining Corporation TOLL FREE (800) 460-5031 or (819) 825-8088, (FAX) (819) 825-1199 Website: www.nsmgold.com

THE TSX VENTURE EXCHANGE HAS NOT REVIEWED THE PRESENT INFORMATION AND IS NOT RESPONSIBLE FOR THE CONTENTS OF THIS NEWS RELEASE, WHICH MAY CONTAIN FORWARD LOOKING STATEMENTS.