X0202 4 2006-04-10 0 0000075129 OTTER TAIL CORP OTTR 0001278053 MACFARLANE CHARLES S 215 S CASCADE ST FERGUS FALLS MN 56537-2801 0 1 0 0 President, Otter Tail Power Co Common Stock 2006-04-10 4 F 0 771 28.235 D 4250 D Restricted Stock Units 2006-04-10 4 A 0 4300 0.00 A 2010-04-08 Common Stock 4300 4300 D Grants of Restricted Stock. On 4/10/2006, 771 shares were withheld by the Corporation to pay taxes due upon vesting of restricted stock, exempt pursuant to Rule 16b-3(e). 4,250 shares remain restricted. See below for other holdings: 1. Direct holding of 730 shares. 2. Direct holding of 5,241.4458 shares held in the Dividend Reinvestment Plan. 3. Direct holding of 4,660 shares which no longer carries the restriction. 4. Direct holding of 3,618.4073 shares held in the Employee Stock Purchase Plan. 5. Indirect holding of 642.3866 shares held by ESOP. 6. Indirect holding of 154.891 shares held by his children in custodian accounts. 7. 10,000 stock options with expiration date of 12/9/2011. 8. 3,000 stock options with expiration date of 4/7/2012. 9. 8,000 stock options with expiration date of 4/13/2013. 10. 3,000 stock options with expiration date of 4/11/2014. 11. 3,000 stock options with expiration date of 4/10/2015. One for one. These units vest 100% on 4/8/2010 based on continued employment. These restricted stock units vest 100% on 4/8/2010 based on continued employment and carry no voting rights or rights to dividends prior to vesting date. /s/ Charles S MacFarlane by Debra J Lill -POA 2006-04-12