X0202 4 2007-08-20 0 0000075129 OTTER TAIL CORP OTTR 0001191493 KOECK GEORGE A 215 S CASCADE ST FERGUS FALLS MN 56537-2801 0 1 0 0 Corp Secretary & Gen Counsel Common Stock 2007-08-20 4 M 0 6600 26.25 A 6600 D Common Stock 2007-08-20 4 S 0 100 37.00 D 6500 D Common Stock 2007-08-20 4 S 0 200 37.01 D 6300 D Common Stock 2007-08-20 4 S 0 200 37.03 D 6100 D Common Stock 2007-08-20 4 S 0 200 37.11 D 5900 D Common Stock 2007-08-20 4 S 0 200 37.12 D 5700 D Common Stock 2007-08-20 4 S 0 202 37.13 D 5498 D Common Stock 2007-08-20 4 S 0 400 37.14 D 5098 D Common Stock 2007-08-20 4 S 0 98 37.15 D 5000 D Common Stock 2007-08-20 4 S 0 300 37.24 D 4700 D Common Stock 2007-08-20 4 S 0 100 37.25 D 4600 D Common Stock 2007-08-20 4 S 0 100 37.26 D 4500 D Common Stock 2007-08-20 4 S 0 295 37.27 D 4205 D Common Stock 2007-08-20 4 S 0 100 37.34 D 4105 D Common Stock 2007-08-20 4 S 0 100 37.36 D 4005 D Common Stock 2007-08-20 4 S 0 500 37.47 D 3505 D Common Stock 2007-08-20 4 S 0 5 37.49 D 3500 D Common Stock 2007-08-20 4 S 0 500 37.50 D 3000 D Common Stock 2007-08-20 4 S 0 300 37.53 D 2700 D Common Stock 2007-08-20 4 S 0 100 37.55 D 2600 D Common Stock 2007-08-20 4 S 0 500 37.56 D 2100 D Common Stock 2007-08-20 4 S 0 300 37.58 D 1800 D Common Stock 2007-08-20 4 S 0 200 37.59 D 1600 D Common Stock 2007-08-20 4 S 0 1 37.62 D 1599 D Common Stock 2007-08-20 4 S 0 1 37.63 D 1598 D Common Stock 2007-08-20 4 S 0 200 37.65 D 1398 D Common Stock 2007-08-20 4 S 0 200 37.66 D 1198 D Common Stock 2007-08-20 4 S 0 199 37.67 D 999 D Common Stock 2007-08-20 4 S 0 199 37.68 D 800 D Common Stock 2007-08-20 4 S 0 300 37.90 D 500 D Stock Options (right to buy) 26.25 2007-08-20 4 M 0 6600 0.00 D 2011-04-09 Common Stock 20000 3400 D There is no specific "Exercisable Date" on these Stock Options. This report is 1 of 2 for Form 4 filing on George A Koeck. /s/ George A Koeck by Debra J Lill -POA 2007-08-21