Rimfire Minerals Corporation

Rimfire Minerals Corporation
Serengeti Resources Inc.

Serengeti Resources Inc.

April 05, 2005 08:30 ET

Rimfire Minerals Corporation and Serengeti Resources Inc.: Tide Airborne Survey Underway/Preliminary Metallurgical Testwork Completed






APRIL 5, 2005 - 08:30 ET

Rimfire Minerals Corporation and Serengeti Resources
Inc.: Tide Airborne Survey Underway/Preliminary
Metallurgical Testwork Completed

VANCOUVER, BRITISH COLUMBIA--(CCNMatthews - April 5, 2005) - Rimfire
Minerals Corporation (TSX VENTURE:RFM) and Serengeti Resources Inc. (TSX
VENTURE:SIR) are pleased to report favourable metallurgical results and
the commencement of airborne geophysical surveying at the Tide Property,
located 36 kilometres north of the port of Stewart, BC.

The 2005 field programs at the Tide will focus on advancing the 36 Zone
gold discovery where TIDE04-03 intersected 1.00 g/t gold over 129.4
metres, including a 39.6 metre intersection averaging 1.92 g/t gold.
This is the first and only drill hole to test the 36 Zone soil
geochemical anomaly, a 450 x 350 metre, greater than 0.5 g/t gold in
soil anomaly that remains open in all directions.

Preliminary metallurgical testing of the 36 Zone has been completed on
four drill hole intervals, each of which was comprised of 50 gram splits
from eight original sample pulps from TIDE04-03. Bottle roll cyanidation
tests returned favourable gold leach recoveries of 78%-87%. Test results
for three of the samples indicated that a high proportion of the gold is
liberated after only 2 hours of leaching with the fourth sample
improving from 71% recovery to 82% after only 4 hours of leaching.
Cyanide consumption averaged 0.6 kg/t for the four samples tested.
Canadian Environmental and Metallurgical Inc. conducted the tests under
the direction of Global Discovery Labs, both of Vancouver, B.C. A more
detailed metallurgical study is currently being undertaken on drill core
to optimize recovery rates.

The current program consists of 315 line kilometres of airborne magnetic
and electromagnetic geophysical surveying flown at a line-spacing of 100
metres. This detailed geophysical surveying, in conjunction with
geological and geochemical data, will aid in targeting drilling at the
36 Zone and other targets. Aeroquest Limited of Ontario has been
contracted to complete the airborne survey.

Following completion of the airborne surveying, a second phase of work
will start when conditions are suitable for ground-based exploration
including core drilling, prospecting, mapping and in-fill geochemical

Rimfire and Serengeti were attracted to the Tide Property by its large
soil and silt geochemical anomalies, the extent and high grades of its
polymetallic mineralization, favourable infrastructure and breadth of
mineralization in the Stewart-Sulphurets corridor. The
Stewart-Sulphurets gold camp hosts such deposits as the Kerr-Sulphurets
Gold deposits (3.4 million oz. gold) and Silbak-Premier Mine (2.1
million oz. gold, 43 million oz. silver).

Mineralization on the Tide Property is related to a 200-1000 metre wide,
hornblende-feldspar porphyry sill complex, an offshoot of the lower
Jurassic Summit Lake Stock. Modern exploration of the Property, dating
back to 1979, has identified 13 precious metal showings within a 7
square kilometer area. Work to date has indicated that the property has
the potential to host both bulk tonnage targets (36 Zone) distal to the
porphyry sill and high grade veins (52 Zone which returned grades up to
593 g/t gold and 14,708 g/t silver from a 0.5 metre representative grab
sample) both within the sill and peripheral to it.

Rimfire purchased the Tide Property outright from Newmont Exploration
Canada Limited in 2001, subject to a 1.5% Net Smelter Royalty (NSR).
Serengeti is earning a 51% interest in the Tide Property by spending
$1.435 million in exploration, paying $100,000 cash and issuing 325,000
shares by 2007. Rimfire is acting as project operator.

Rimfire is an aggressive, well-financed mineral exploration company with
a portfolio of highly prospective gold and silver properties in the
western Cordillera. Partners include AngloGold (U.S.A.) Exploration
Inc., Barrick Gold Corporation, Newmont Mining Corporation, Northgate
Minerals Corporation, Cangold Limited, and Serengeti Resources Inc.

Serengeti is a mineral exploration company, under experienced new
management who bring a solid track record of discovery. Serengeti is
focused on discovery of copper-gold and gold-silver deposits in British
Columbia, especially in the highly prospective Quesnel Trough and
Stewart mining camp.

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 the Companies' qualified persons,
David Caulfield, P. Geo., President and CEO of Rimfire Minerals
Corporation and David W. Moore, P. Geo., President and CEO of Serengeti
Resources Inc.


Contact Information

    Rimfire Minerals Corporation
    David A. Caulfield
    President and CEO
    (604) 669-6660
    Rimfire Minerals Corporation
    Jason Weber
    Manager, Corporate Communications
    (604) 669-6660
    Serengeti Resources Inc.
    David W. Moore
    President and CEO
    (604) 689-7761
    Serengeti Resources Inc.
    Robert Ferguson
    Investor Relations, Freeform Communications Inc.
    (778) 371-9100
    The TSX Venture Exchange has neither approved nor disapproved the
    contents of this news release.