Rimfire Minerals Corporation

Rimfire Minerals Corporation

November 19, 2007 10:36 ET

Rimfire and Island Arc Commence Drilling at Jake

VANCOUVER, BRITISH COLUMBIA--(Marketwire - Nov. 19, 2007) - David Caulfield, President and CEO of Rimfire Minerals Corporation ("Rimfire") (TSX VENTURE:RFM) is pleased to report the commencement of drilling at the Jake Property, 13 kilometres west of Clearwater, British Columbia. Island Arc Exploration Corporation is funding the program under an option agreement to earn a 51% interest in the property by funding $1.75 million in expenditures over 3 years. The program is budgeted for 900 metres of drilling in seven holes testing three targets. This work follows IP geophysical surveys and trenching completed earlier in 2007.

An IP survey conducted in June revealed three chargeability high anomalies in the immediate vicinity of the Jake Showing. The first area is coincident with the Jake discovery outcrop, reflecting mineralization sampled in trenches in 2006 and 2007 programs. Results of 2007 trenching include 7.70 g/t gold over 2.80 metres from a channel sample across a series of quartz-pyrrhotite-pyrite-chalcopyrite-bismuthinite veins, including 19.3 g/t gold over 0.60 metres. A second anomaly (the "Jake Offset") lies 300 metres to the north of the Jake Showing, trending to the northwest over a distance of 300 metres in length and open to the northwest. This IP anomaly is parallel to narrow mineralized structures observed in a trench located on its west flank that consist of 0.10 - 0.25 metre wide, northwest-oriented auriferous pyrrhotite-chalcopyrite-pyrite-bismuthinite veins. Results from this trench include 12.5 g/t gold over 0.1 metres. Due to the depth of glacial overburden, trenching was unable to reach bedrock in the area of the highest chargeability in this anomaly. Gold mineralization in these adjacent structures is associated with elevated copper and bismuth geochemistry and strongly suggests that the adjacent untested IP anomaly may be a fault offset of the Jake Showing which is characterized by a similar geochemical signature.

A third chargeability anomaly lies approximately 225 metres east of the Jake Showing and is open to the south and east. Immediately west of this anomaly, one trench exposed a 1.0 metre wide, north-northwest-oriented fault structure with associated auriferous quartz-pyrrhotite-chalcopyrite-arsenopyrite veins. Similar to the Jake Offset, these veins occur on the western flank of an untested chargeability high.

"The 2007 IP survey was successful in expanding our target area beyond the limits of the Jake Showing. While we were unable to investigate the highest chargeability portions of the two new anomalies by trenching, veining on the flanks is anomalous in gold with associated copper and bismuth," stated Mark Baknes, VP Exploration for Rimfire. "If the chargeability anomalies do reflect buried veins similar to those at the Jake Showing, we will have a valuable tool for targeting drilling in a largely overburden covered area."

All samples were analyzed by ALS Chemex, North Vancouver, BC, using ICP-MS and AES analyses for trace element geochemistry and fire assay for gold. The results contained in this news release have been reviewed by Mark Baknes, M.Sc., P.Geo., Vice President Exploration, a Qualified Person under National Instrument 43-101.
About Rimfire

Rimfire Minerals Corporation is an aggressive, well-financed mineral exploration company with a portfolio of highly prospective gold and silver properties in western North America. Current and former partners include AngloGold Ashanti Limited, Barrick Gold Corporation, Newmont Mining Company, Northgate Minerals Corporation, Fronteer Development Group, Rubicon Minerals Corporation, Cangold Limited, American Creek Resources Ltd., Island Arc Exploration Corporation, Arcus Development Group Inc. and BWG.

On behalf of Rimfire Minerals Corporation

David A. Caulfield, President

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

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