AMENDMENT TO THE POTLATCH CORPORATION SALARIED EMPLOYEES' SUPPLEMENTAL BENEFIT PLAN

Exhibit 10.5

AMENDMENT TO THE

POTLATCH CORPORATION

SALARIED EMPLOYEES’ SUPPLEMENTAL BENEFIT PLAN

The Potlatch Corporation Salaried Employees’ Supplemental Benefit Plan, as amended through May 24, 2005 (the “Plan”), is hereby further amended as follows, effective as of January 1, 2009:

Section 3(b) of the Plan is hereby amended by revising the second paragraph thereof to read as follows:

“Through December 31 of the Plan Year preceding the Plan Year in which payment of the Participant’s entire Savings Plan Supplemental Benefit is made, the amount credited to such bookkeeping account shall be credited with earnings and losses based on the following:

(i) For periods prior to January 1, 2009, earnings shall be calculated using an interest rate equal to 70% of the higher of the following averages, compounded annually: (i) the prime rate charged by the major commercial banks as of the fir