past, and they were ready to move forward once more. Between 1940 and 1944, Otter Tail added territory by merger or acquisition of 6 smaller power companies within or adjacent to its territory (almost all of who had corporate parents that were required to divest these properties due to passage of the Public Utility Holding Company Act of 1935). These purchases increased its territory to its present size of , about the same size as the state of Wisconsin. The one exception in this territory is the Red River Valley between Grand Forks and Fargo, ND, which was then and still is served by Northern States Power Company (now Xcel Energy). After the final major acquisition in 1944, the company had reached its 'maximum system' of 496 towns served at both retail and wholesale. As the company matured over the next several decades, the number of towns served within the region would shrink (mainly due to towns served at wholesale changing suppliers and some smaller retail towns dying out). A few towns were added between 1944 and 1968—the largest being the purchase of Fergus Falls' municipal utility in 1953 and the last addition being the transfer of several towns in Polk County, Minnesota, from Northern States Power Company when the 34.5 kV transmission line serving these towns approached its load limit. A merger with Montana-Dakota Utilities was briefly explored in the late 1960s but was soon dropped due to all the regulatory hurdles involved. By the 1990s, flat revenues from the utility operations led the company to establish a subsidiary (Varistar) to acquire and oversee non-utility businesses. In 2001, the company changed its name to Otter Tail Corporation with the utility becoming a division within the company. In late 2008, the company completed a reorganization to realign the utility operations into a subsidiary within Otter Tail Corporation. Hydropower In the beginning, Otter Tail Power built a series of hydroelectric plants to provide power for its system and these served the company well until its expansion in the 1920s outstripped the dams' capacity (steam provided the bulk of the company's power needs from then on). The company has grown to such a point that today only about 1% of the company's needs still comes from hydropower. The dams are: Dayton Hollow (1909 - southwest of Fergus Falls), Hoot Lake (1914 / 1918 - east Fergus Falls), Pisgah (1918 - west Fergus