Rimfire Minerals Corporation
TSX VENTURE : RFM

Rimfire Minerals Corporation

August 13, 2007 09:35 ET

Rimfire Minerals Corporation: Drilling Intersects Gold Mineralization in Alaska

VANCOUVER, BRITISH COLUMBIA--(Marketwire - Aug. 13, 2007) - David Caulfield, President and CEO of Rimfire Minerals Corporation ("Rimfire") (TSX VENTURE:RFM) is pleased to report that drilling in the Goodpaster District has intersected a 7.4 metre-wide gold-bearing zone of quartz veining at the California North target. Based on this intersection, further drilling is planned this year.

"We are very encouraged that we have a wide, gold-bearing intersection at the California North target," stated Mark Baknes, VP Exploration for Rimfire. "Our objective now is to get an accurate measurement of the vein thickness and orientation by further drilling."

Rubicon Minerals Corporation funded this drilling program (totalling 957 metres) to test four widely spaced targets on the Cal-Surf Property in the Goodpaster District, Alaska. Exploration in the district is targeting high grade gold-bearing quartz vein deposits. The Cal-Surf Property is located approximately 15 kilometres east of the Pogo Gold Mine.

Hole CN07-01 was drilled to test the California North gold and arsenic soil geochemical anomaly. Quartz vein mineralization was intersected at a depth of 72.6 metres and averaged 1.2 g/t gold over a 7.4 metre width including 2.5 metres averaging 2.2 g/t gold. Extremely fractured core and poor core recovery did not allow for an accurate measurement of true vein thickness. At least one additional hole is planned for the target to determine the true thickness and orientation of the vein. Drilling is planned to commence in mid-August.

Additional holes were completed at two new targets at the Beverly and Blue grids and a third at the Boundary Zone, where drilling in 2000 and 2001 intersected high grade gold mineralization in quartz-sulphide veinlets. These holes returned only low gold +/- bismuth values.

In conjunction with the drilling campaign, groundwork was undertaken at the Cal-Surf, Eagle and Swede properties, returning anomalous gold and pathfinder element geochemistry in soil samples that warrant further investigation.

Rimfire has held key ground in the Goodpaster District since the discovery of the Pogo Deposit was announced by Teck Cominco in the late 1990's. To date, Rimfire has identified gold targets on four individual properties on trend and in the vicinity of the Pogo Mine property. In January of 2007, Rimfire's 182,320 acre land package was optioned to Evanachan Limited, a private company controlled by ex-Goldcorp Chairman and CEO Robert McEwen. In a recently completed $22 million transaction, Rubicon purchased Evanachan's Alaskan holdings, including the option on Rimfire's properties. Rubicon funded the 2007 program as part of its option to earn a 60% interest in the group of four properties by completing $4.8 million in exploration over six years. Rubicon can earn another 10% by completing a feasibility study and a further 5%, at Rimfire's election, by providing a project financing loan to be repaid from Rimfire's free cash flow upon production.

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. Rimfire is partnered with 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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