Stock Basis Calculator

Dear Shareholder:

We are providing an Excel® model to assist you in the estimation of your tax basis in Potlatch Corporation common stock taking into account the distribution of earnings and profits in 2006, when we elected to be taxed as a Real Estate Investment Trust, (REIT), spinoff of Clearwater Paper Corporation, and return of capital distributions that may have taken place subsequent to your purchase of our stock, if any. Each Shareholder's tax position may vary. Shareholders are encouraged to consult their tax adviser regarding their individual tax situation.

To use the model you need the following information:

Original date of purchase
Date of sale if sold
Number of shares purchased
Cost per share
Expenses of purchase such as broker commissions and transfer fees
Amount of cash received in 2006 as the "special dividend" if owned on February 14, 2006

ALL COMPUTATIONS ASSUME THAT YOU HAVE ELECTED TO DETERMINE YOUR STOCK BASIS UNDER
§ 1012(a) - THE ACTUAL COST OF THE SHARES OF STOCK FOR WHICH BASIS IS BEING DETERMINED.

OTHER NON-CORPORATE EVENTS SPECIFIC TO YOU AS A SHAREHOLDER MAY IMPACT YOUR SHARE BASIS AND ARE NOT CONSIDERED IN THIS TOOL - CONSULT YOUR TAX ADVISOR

THIS TOOL DOES NOT CONSIDER THE IMPACT OF A WASH SALE - CONSULT YOUR TAX ADVISOR

TO BEGIN CLICK HERE