Press Release Detail 5.23

Vancouver, BC - Wheaton River Minerals Ltd. (“Wheaton”) (TSX: WRM; AMEX: WHT), recently acquired by Goldcorp Inc (TSX: G; NYSE GG), is pleased to report record levels of gold reserves and resources as of December 31, 2004, summarized as follows:

• Proven and Probable gold reserves have increased to 5.1 million ounces;
• Measured and Indicated resources have increased to 3.7 million ounces; and
• Inferred resources have increased to 5.1 million ounces.

Ian Telfer, Chairman & Chief Executive Officer of the Company said: “Nearly one million gold ounces were added to the reserve base during 2004, almost double the year’s production of 513,000 ounces.  Wheaton has also exceeded 5 million ounces of Proven and Probable gold reserves for the first time in company history.  When you combine this organic growth in reserves and resources with our record gold production and cost achievements of 2004, the strength of our operating team stands out.”

Notes:

1. All Mineral Reserves and Mineral Resources have been calculated as of December 31, 2004 in accordance with the standards of the Canadian Institute of Mining, Metallurgy and Petroleum and National Instrument 43-101, or the AusIMM JORC equivalent.
   
   
2. Data shown is Wheaton River’s share of reserves and resources.
   
   
3. All Mineral Resources are exclusive of Mineral Reserves.
   
   
4. Mineral Resources which are not Mineral Reserves do not have demonstrated economic viability.
   
   
5. Qualified Persons for the Mineral Reserve and Mineral Resource estimates as defined by the National Instrument 43-101 are as follows:
   1. Luismin - San Dimas and San Martin reserves and resources          Reynaldo Rivera, AusIMM, Luismin S.A. de C.V.
   2. Luismin – Nukay reserves and resources          Gary Giroux. P.Eng., Micon Consultants
   3. Los Filos resources          Neil Burns, P.Geo., Snowden Mineral Industry Consultant
   4. El Limon resources          James N. Grey, P.Geo., Al Samis, P.Geo., Teck Cominco Ltd.
   5. Alumbrera reserves and resources          Luis Rivera, AusIMM, Minera Alumbrera Ltd.
   6. Peak Gold reserves          Joe Ranford, AusIMM, Peak Gold Mines
   7. Peak Gold resources          Rex Berthelsen, AusIMM, Peak Gold Mines
   8. Amapari reserves and resources        Rodrigo Mello, AusIMM, Wheaton Gold Brazil
   9. Wheaton River Corporate          Randy V.J. Smallwood, P.Eng., Wheaton River Minerals Ltd.
6. Mineral Reserves and Mineral Resources are estimated using appropriate recovery rates and commodity prices as follows;
   1. San Dimas, San Martin, Nukay, Peak, Amapari - US$ 375 per ounce of gold, US$ 5.50 per ounce of silver (where applicable), and US$ 0.95 per pound of copper (where applicable)
   2. Alumbrera reserves -  US$ 350 per ounce of gold, US$ 0.90 per pound of copper
   3. Los Filos, El Limon, Alumbrera resources – wholly contained within an optimization shell defined by using US$ 400 per ounce of gold and US$ 1.00 per pound of copper (where applicable)
7. For a detailed breakdown of Proven and Probable Reserves, and Measured, Indicated and Inferred Resources please reference the supplemental information attached at the end of this press release, or visit www.wheatonriver.com.

Reserve and Resource Growth

Luismin         For the first time ever the prolific San Dimas camp has exceeded one million gold equivalent ounces in proven and probable reserves.  Surface and underground drilling continues to define a high grade east-west regional trend through the centre of this district, and the new tunnel to access these vein systems at depth is advancing ahead of schedule.  At the San Martin operation, development of theCuerpo 31 orebody is progressing on schedule and first ore was delivered from this orebody during 2004.  Drilling from both surface and underground continues to define and expand the northern and depth extents of this orebody.

Los Filos       The December 31, 2004 resource is reported within a US$ 400 gold optimized pit shell, and includes crush/leach resources of 51 million measured and indicated tonnes grading 1.28 grams of gold per tonne for a total of 2.1 million ounces.  In addition, metallurgical testing during the year has shown that a large amount of lower grade material previously defined as uneconomic can be profitably run-of-mine leached.  Since acquisition, drilling and metallurgical improvements have increased the global measured and indicated resource ounces at Los Filos by 41%.

El Limon       During 2004 drilling was focused on defining the limits of the Guajes West orebody and testing extensions to the south of the Limon Sur deposit.  Over the year, inferred resources at this deposit were increased by 63% to over 3 million ounces, all contained within a US$ 400 gold pit optimization shell.  An infill drilling campaign is expected to begin during 2005.

Peak               Since the acquisition of Peak in mid 2003, gold ounces contained in resources have now more than doubled. 2005 drilling will focus on advancing these resource ounces into the reserve base.

Alumbrera    A significant drilling program was conducted during 2004, adding more than two years of operating life to this world class operation.  At the end of 2004, another 30 million tonnes were added as measured and indicated resources.

Amapari        Since acquisition in January 2004 the Company has conducteda successful infill and step-out drilling program.  Studies have demonstrated that open pit mining of a portion of the sulphide reserves is feasible, and the consequent decrease in operating costs per tonne has resulted in a significant amount  of lower grade material becoming economically mineable.  Cash costs are expected to remain in line with previous projections of US$ 137 per ounces of gold.  Production is expected to commence in Q3 2005.

In February 2005, Goldcorp announced that it’s offer for Wheaton River Minerals was successful and this merger is expected to be finalized in April 2005. The combined company, which will continue as Goldcorp, creates the world’s lowest cost, million ounce gold producer, with 2005 gold production expected to exceed 1.1 million ounces of gold at a cash cost of less than US$60 per ounce. By 2007, gold production is expected to grow to 1.5 million ounces with commencement of operation at Los Filos and Amapari and the expansion at Red Lake Mine.  The combined company will have a strong balance sheet with over $500 million in cash and gold bullion, and no debt.

Cautionary Statements

Safe Harbor Statement under the United States Private Securities Litigation Reform Act of 1995: Except for the statements of historical fact contained herein, the information presented constitutes “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements, including but not limited to those with respect to the price of gold, silver and copper, the timing and amount of estimated future production, costs of production, reserve determination and reserve conversion rates involve known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of Wheaton River to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. Such factors include, among others, risks related to the integration of acquisitions, risks related to international operations, risks related to joint venture operations, the actual results of current exploration activities, actual results of current reclamation activities, conclusions of economic evaluations, changes in project parameters as plans continue to be refined, future prices of gold, silver and copper, as well as those factors discussed in the section entitled “Risk Factors” in the Form 40-F for the company on file with the U.S. Securities and Exchange Commission in Washington, D.C. Although Wheaton River has attempted to identify important factors that could cause actual results to differ materially, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that such statements will prove to be accurate as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements.

United States investors are advised that, such terms are recognized and required by Canadian regulations, the U.S. Securities and Exchange Commission does not recognize them. “Inferred Resources” have a great amount of uncertainty as to their existence, and great uncertainty as to their economic and legal feasibility.  It cannot be assumed that all or any part of an “Inferred Resource” will ever be upgraded to a higher category.  Under Canadian rules, estimates of Inferred Resources may not form the basis of feasibility or other economic studies.  U.S. investors are cautioned  not to assume that all or any part of Measured or Indicated Resources will ever be converted into Reserves.  U.S. investors are also cautioned not to assume that all or any part of an Inferred Mineral Resource exists, or is economically or legally mineable.