Week of May 12, 2008

Date	Open	High	Low	Close	Volume
May 12, 2008	36.12	36.50	35.70	36.18	147,663
May 13, 2008	36.22	36.31	35.59	36.29	158,163
May 14, 2008	36.30	36.47	35.84	36.14	142,724
May 15, 2008	36.25	36.89	36.02	36.70	209,185
May 16, 2008	36.91	37.13	36.10	36.75	220,916

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Year End Stock Prices

The historical stock information provided is for informational purposes only and is not intended for trading purposes. The historical stock information is provided by Mergent, a third party service, and Otter Tail Corporation does not maintain or provide information directly to this service. Prices display split-adjusted cost basis per share on that date.