Wind Power Factory Watch: DMI Hires for Tulsa

FOR IMMEDIATE RELEASE

DMI INDUSTRIES FINALIZES TULSA PLANT ACQUISITION
Wind Tower Manufacturer Begins Hiring, Plans to Take On Up To 450 People

West Fargo, N.D. (Aug. 16, 2007) – DMI Industries is looking for a few hundred good people.

The West Fargo, N.D.-based wind tower manufacturer is opening a plant at 15300 Tiger Switch Road in Tulsa, Okla. and expects to eventually employ up to 450 people there. The company needs at least 200 employees to get started, and is holding a job fair at the Renaissance Hotel on Tuesday, August 21 to begin filling positions.

“We’re extremely pleased to be in Tulsa, a community with a reputation for good, hard-working and dedicated people,” said DMI President Lars Møller. “We need a strong team to build state-of-the-art wind towers, to begin having a positive impact on the local and regional economies, and to continue improving service and lowering costs for our customers.”

DMI began modernizing its Tulsa facility immediately after acquisition, and it is expected to be operational in early 2008. In addition to the positive impacts of construction and trade jobs for the plant’s renovation, the plant will provide substantial ongoing direct and indirect economic impacts in the Tulsa region. When it is economically feasible, DMI also will engage local and regional suppliers to meet the plant’s day-to-day operational needs.

“DMI’s selection of Tulsa to expand its wind tower manufacturing is another great addition to our list of diverse industries,” said Tulsa Mayor Kathy Taylor. “DMI is well-positioned in its marketplace with a prominent customer base, especially as regions across the nation expand efforts to increase utilization of ‘green’ energy sources.”

DMI plans to hire the vast majority of employees locally, including welders, painters and steel plate rollers, as well as general management, supervisory, human resources and administrative personnel. Tulsa employees will be trained on site and in the company’s West Fargo and Fort Erie facilities.

In addition to the city, Møller credited the Tulsa Metro Chamber, the Rogers County Industrial Development Authority and the Oklahoma Department of Commerce with convincing DMI to locate in the Tulsa area.

“Today’s announcement takes another prime property off of the available list in Tulsa,” said Mike Neal, Chamber president and CEO. “It also is another example of the Chamber’s efforts to recruit progressive, high-quality jobs to the metro region. The economic impact of approximately 450 jobs with DMI will support an additional 540 indirect jobs in the metro region and generate a total economic impact of $157 million in goods and services.”

The Tulsa plant will feature half a million square feet of production space. With it and the company’s two existing plants, in West Fargo and Fort Erie, Ontario, DMI’s annual combined tower production will support more than 3,000 MW of installed wind project capacity, based on today’s tower and turbine technologies and designs.

The Oklahoma facility is the second new plant acquisition for DMI in two years. The company acquired its Fort Erie facility in 2005 and it became fully operational in May 2006. It currently employs 540 people in Fort Erie and West Fargo.

DMI, an operating company of Otter Tail Corporation, is a heavy steel wind tower manufacturer. The company also has capabilities to produce equipment for a wide variety of industries, including agricultural processing; ethanol production; oil and gas extraction, processing and refining; and water and waste water processing. For more information, visit www.windtowers.com or www.dmiindustries.com.

Otter Tail Corporation has interests in diversified operations that include an electric utility, plastics, manufacturing, health services, food ingredient processing, transportation and construction. Otter Tail Corporation stock trades on the NASDAQ Global Select Market under the symbol OTTR. The latest investor and corporate information is available at www.ottertail.com. Corporate offices are located in Fergus Falls, Minn., and Fargo, N.D.

Forward-looking Statements

Except for historical information, all other information provided in this presentation consists of “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. These “forward-looking statements” are subject to risks and uncertainties which could cause actual results to differ materially from those projected, anticipated, or implied. The most significant of these risks and uncertainties are discussed or identified in Otter Tail Corporation’s public filings made with the Securities and Exchange Commission. Otter Tail Corporation undertakes no obligation to publicly update or revise any forward-looking statements.

- 30 -