Reserves & Resources

1. All Mineral Reserves and Mineral Resources have been calculated in accordance with the standards of the Canadian Institute of Mining, Metallurgy and Petroleum, National Instrument 43-101, or the AusIMM JORC equivalent.
2. Mineral Reserves and Mineral Resources are reported above in millions of metric tonnes (Mt), grams per metric tonne (g/t), and millions of ounces (Moz).
3. Individual Qualified Persons (QP) for the Mineral Reserve and Mineral Resource estimates as defined by the National Instrument 43-101 are as follows:
   • Peñasquito - Bob Bryson, MMSA
   • San Dimas – Reynaldo Rivera, MAusIMM (Vice-President Exploration), Goldcorp Mexico; Velasquez Spring, P.Eng. (Senior Geologist) Watts, Griffis and McOuat Limited.
   • Pascua-Lama – as disclosed in the Barrick press release dated February 18, 2010.
   • Yauliyacu – Neil Burns, M.Sc., P.Geo., (Director, Geology) and Samuel Mah, M.A.Sc., P.Eng. (Director, Engineering), both employees of the Company (the Company’s QPs)
   The Company QP’s are responsible for overall corporate review and all other operations and development projects.
4. The Mineral Resources reported in this table are exclusive of Mineral Reserves. The Minto, Neves-Corvo and Aljustrel mines report Mineral Resources inclusive of Mineral Reserves. The Company’s QPs have made the exclusive Mineral Resource estimates for these mines based on average mine recoveries and dilution.
5. Mineral Resources which are not Mineral Reserves, do not have demonstrated economic viability.
6. Mineral Reserves and Mineral Resources are reported as of December 31, 2009, other than the following:
   • Resources and Reserves for San Martin are reported as of July 1, 2009 except for San Pedrito which is reported as of December 31, 2006.
   • Resources for Rosemont are reported as of October 22, 2008 and Reserves as of March 17, 2009.
   • Resources and Reserves for Mineral Park are reported as of December 29, 2006.
   • Resources and Reserves for Aljustrel are reported as of December 31, 2007.
   • Resources for Campo Morado are reported as of February 29, 2008.
   • Resources and Reserves for Stratoni are reported as of June 24, 2009.
   • Resources for Loma de la Plata are reported as of April 16, 2009.
   • Resources for Minto are reported as of June 9, 2009 for Area 2, Area 118 and Ridgetop; as of December 1, 2009 for Minto North; and as of December 31, 2008 for Minto Main.
   • Resources and Reserves for Cozamin are reported as of March 31, 2009.
   • Resources for Keno Hill are reported as of November 9, 2009.
   • Resources for La Negra are reported as of February 15, 2008 for the Alacran, March 14, 2008 for the Monica and December 31, 2009 for Maravillas.
7. Process recoveries are the average percentage of silver in a saleable product (dore or concentrate) recovered from mined ore at the applicable site process plants as reported by the operators.
8. Mineral Reserves are estimated using appropriate process recovery rates and commodity prices of US$13 per ounce of silver unless otherwise noted below:
   • San Martin – US$10.00 per ounce
   • Pascua-Lama, Lagunas Norte, Veladero and Pierina – US$14.00 per ounce
   • Neves-Corvo – 1.6% Cu cut-off for the copper reserve and 4.3% Zn cut-off for the zinc Reserve.
   • Rosemont – NSR cut-off of US$3.56 based on US$1.75 per pound copper, US$15.00 per pound molybdenum and US$10.00 per ounce silver.
   • Mineral Park - 0.237% Cu equivalent cut-off grade (hypogene), 0.283% Cu equivalent cut-off grade (supergene). Copper equivalent considers only copper and molybdenum values.
   • Zinkgruvan – 3.1% Zn equivalent cut-off for the zinc Reserve and 2.0% Cu cut-off for the copper Reserve.
   • Aljustrel – 1.5% Cu cut-off for all copper Reserves and zinc cut-offs of 4.5%, 4.0% and 4.0% respectively for the Feitais, Moinho and Estação zinc Reserves.
   • Minto – internal cut-offs of US$24.18 for Minto North, US$25.47 for Ridgetop and US$24.94 for Area 2/ 118 based on a NSR model generated using US$2.00 per pound copper.
   • Cozamin – US$4.00 per ounce
9. Mineral Resources are estimated using appropriate recovery rates and commodity prices of US$15 per ounce of silver, unless otherwise noted below:
   • San Martin (excluding San Pedrito) – US$10.00 per ounce; San Martin (San Pedrito only) – US$5.50 per ounce
   • Pascua-Lama, Lagunas Norte, Veladero, and Pierina - US$14.50 per ounce
   • Yauliyacu – US$13.00 per ounce.
   • Neves-Corvo – 1.0% Cu cut-off for copper Resource and 3.0% Zn cut-off for the zinc Resource.
   • Rosemont – 0.2% Cu cut-off.
   • Zinkgruvan – 3.1% Zn equivalent cut-off for the zinc Resource and 1.5% Cu cut-off for the copper Resource.
   • Mineral Park – 0.225% Cu equivalent cut-off grade. Copper equivalent considers only copper and molybdenum values.
   • Aljustrel – 1.5% Cu cut-off for all copper Resources and zinc cut-offs of 4.5%, 4.0% and 4.0% respectively for the Feitais, Moinho and Estação zinc Resources.
   • Campo Morado – 5.0% Zn only cut-off grade.
   • Loma de la Plata – 50 g/t silver equivalent based on US$12.52 per ounce silver and US$0.50 per pound lead.
   • Minto – 0.5% Cu cut-off.
   • Loma de la Plata – 50 g/t silver equivalent cut-off based on US$12.50 per ounce silver and US$0.50 per pound lead.
   • Cozamin – 1.15% Cu cut-off for San Roberto Area and 3.0% Zn cut-off for San Rafael Area.
   • Keno Hill – US$15.25 per ounce for the Southwest and 99 Zones and US$14.50 per ounce for the East Zone.
   • La Negra (Alacran) – US$12.00 per ounce; La Negra (Monica) – US$13.50 per ounce
10. Los Filos Resources and Reserves are reported without the Bermejal deposit, as Bermejal is not subject to the silver sales agreement.
11. The Company’s attributable tonnage at Lagunas Norte was estimated by assuming 2008 production levels for four years.  This tonnage was pro-rated between Proven and Probable Reserves according to the ratio of the December 31, 2009 Proven and Probable Reserves for Lagunas Norte as published by Barrick, applying average reserve grades.
12. The Company’s attributable tonnage at Veladero is estimated based on a production rate of 85,000 tonnes per day for four years.  This tonnage was pro-rated between Proven and Probable Reserves according to the ratio of the December 31, 2009 Proven and Probable Reserves for Veladero as published by Barrick, applying average reserve grades.
13. The Company’s purchase agreement (March 2006) with Glencore provides for the delivery of up to 4.75 million ounces of silver per year for 20 years so long as production allows.  In the event that silver produced at Yauliyacu in any year totals less than 4.75 million ounces, the maximum amount to be sold to the Company in subsequent years will be increased to make up the shortfall.
14. The Mineral Park and Rosemont Resources and Reserves do not include the SX/EW leach material since this process does not recover silver.
15. The Company has filed a technical report for each of San Dimas, Yauliyacu, Peñasquito and Pascua-Lama on SEDAR.
16. Silver is produced as a by-product metal at all operations with the exception of the Keno Hill project; therefore, the economic cut-off applied to the reporting of silver Resources and Reserves will be influenced by changes in the commodity prices of other metals at the time.

Cautionary Language Regarding Reserves and Resources

Readers should refer to the Annual Information Form of Silver Wheaton for the year ended December 31, 2008 and other continuous disclosure documents filed by Silver Wheaton since January 1, 2009 available on SEDAR at www.sedar.com, for further information on Mineral Reserves and Resources, which is subject to the qualifications and notes set forth therein as well as for additional information relating to the Company more generally. Mineral Resources which are not Mineral Reserves, do not have demonstrated economic viability. Cautionary Note to United States Investors Concerning Estimates of Measured, Indicated and Inferred Resources: These tables use the terms “Measured”, “Indicated” and “Inferred” Resources. United States investors are advised that while such terms are recognized and required by Canadian regulations, the United States Securities and Exchange Commission does not recognize them and expressly prohibits U.S. registered companies from including such terms in their filings with the SEC. “Inferred Mineral Resources” have a great amount of uncertainty as to their existence, and as to their economic and legal feasibility. It cannot be assumed that all or any part of an Inferred Mineral Resource will ever be upgraded to a higher category. Under Canadian rules, estimates of Inferred Mineral Resources may not form the basis of feasibility or other economic studies. United States investors are cautioned not to assume that all or any part of Measured or Indicated Mineral Resources will ever be converted into Mineral Reserves. United States investors are also cautioned not to assume that all or any part of an Inferred Mineral Resource exists, or is economically or legally mineable. United States investors are urged to consider closely the disclosure in Silver Wheaton’s Form 40-F, a copy of which may be obtained from Silver Wheaton or from http://www.sec.gov/edgar.shtml