Rimfire and Serengeti Commence Drill Program on the Tide Property.

VANCOUVER, British Columbia -- Henry Awmack, Chairman of Rimfire Minerals Corporation (TSX VENTURE:RFM) is pleased to report that diamond drilling at the Tide Property, funded by partner Serengeti Resources Inc., has started. This phase two program will consist of approximately 600 metres of drilling to test four different target areas. The Tide is favourably located 40 km north of the deep-water port of Stewart, in northwest British Columbia, and is accessible via the Granduc Mine road.

2004 Surface Exploration Results

The recent phase one exploration program consisted of soil sampling, prospecting and geological mapping. This program helped define a 2000 by 600 metre gold-in-soil anomaly exceeding 90 parts per billion (ppb) cored by a zone of anomalous copper, molybdenum and silver values in the central part of the property. This anomaly may reflect a newly recognized porphyry system, overprinted by later gold-silver-base metal veins. Peripheral to this central area are the gold-arsenic bearing 36 Zone and South Pit Zones as well as a newly identified soil geochemical anomaly on the northern part of the property. This anomaly measures 650 by 400 metres of greater than 90 ppb gold, with a core of elevated arsenic, molybdenum and antimony. Rock sampling in these areas and across the property returned 44 (of a total 104) samples assaying greater than 1 gram per tonne (g/t) gold of which 14 assayed greater than 5 g/t gold. Follow up surface work within these newly identified soil anomalies will be undertaken in conjunction with the drill program.

Drill Targets

Diamond drilling will target the 36 Zone, South Pit Zone, Arrow Structure, and the newly identified porphyry style copper-gold-molybdenum mineralization and associated extensive soil geochemical anomalies. The 36 Zone is a bulk tonnage gold target where gold-bearing sheeted quartz-pyrite-arsenopyrite veins are exposed over a 250 by 150 metre area lying within a larger gold-in-soil anomaly of greater than 1000 ppb. Drilling will target anomalous rock samples collected by a previous operator ranging from 1.9 to 10.3 g/t. The newly recognized gold-copper-molybdenum porphyry target will be tested in conjunction with gold-silver-lead-zinc bearing massive sulphide veins at the High Grade Vein, Arrow Structure and newly recognized Brown Bear Zone. Assays of 8.1 g/t gold and 1958 g/t silver across 0.97 metres have been previously reported from the High Grade Vein. The South Pit Zone is located within an area of anomalous soil geochemistry 600 by 250 metres wide containing greater than 1000 ppb gold. Drilling will target a 15 metre wide alteration zone hosting quartz-arsenopyrite veins assaying 4.6 g/t gold over 2 metres and 4.4 g/t gold over 1 metre.

Serengeti and Rimfire management are pleased with the recognition of a potential porphyry gold-copper-molybdenum system associated with the known high grade gold-silver veins and with the expansion and identification of new soil geochemical anomalies on the property.

Assays from the current program were completed at ALS Chemex in North Vancouver, BC. Disclosure of prior results was made in a technical report filed on SEDAR on February 23, 2004. The technical information in this news release has been prepared in accordance with Canadian regulatory requirements set out in National Instrument 43-101 and reviewed by our qualified person, David Caulfield, P. Geo. President, C.E.O Rimfire Minerals Corporation.

Exploration Update

Rimfire is awaiting results from a number of recently completed drilling and reconnaissance exploration projects, including drilling funded by AngloGold and Northgate Minerals at the ER and RDN projects in Alaska and British Columbia, respectively. Reconnaissance exploration has been completed at the wholly-owned Sutlahine Project, a 170 sq. km claim package northwest of the Thorn Property in northwest British Columbia. Newmont and Rimfire have also completed the initial phase of reconnaissance under terms of the Targeted Exploration Alliance agreement.

Three drilling programs are underway or about to commence. In addition to the Tide drilling program, Rimfire will initiate a drill campaign at the Thorn to test the continuity of Oban Breccia Zone mineralization on strike and at depth, and IP geophysical targets generated in 2004 surveying. The third program is currently underway on the Eagle Property in Alaska, funded by AngloGold.

Results from these programs will be released once all data has been compiled and verified.

On behalf of Rimfire Minerals Corporation

Henry Awmack, Chairman

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