X0303 4 2008-10-10 0001254370 WESTERN ASSET CLAYMORE INFLATION-LINKED SECURITIES & INCOME FUND WIA 0001052192 CASCADE INVESTMENT LLC 2365 CARILLON POINT KIRKLAND WA 98033 0 0 1 0 0000902012 GATES WILLIAM H III ONE MICROSOFT WAY REDMOND WA 98052 0 0 1 0 Common Shares of Beneficial Interest 2008-10-10 4 P 0 42000 8.7757 A 4166310 D This transaction was executed in multiple trades at prices ranging from $8.60 to $9.00. The price reported above reflects the weighted average purchase price. The reporting persons hereby undertake to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transactions were effected. * Duly authorized under Special Power of Attorney appointing Michael Larson attorney-in-fact, dated February 3, 2006, by and on behalf of William H. Gates III, filed as Exhibit 99.1 to Cascade Investment, L.L.C.'s Amendment No. 2 to Schedule 13G with respect to Arch Capital Group Ltd. on March 7, 2006, SEC File No. 005-45257, and incorporated by reference herein. By: Cascade Investment, L.L.C. By: /s/ Michael Larson, Business Manager 2008-10-14 By: William H Gates III By: /s/ Michael Larson*, Attorney-In-Fact 2008-10-14