Arrowhead Substation DC to AC Converter, Minnesota

This electrical substation is the terminus for the 450-mile long Square Butte Transmission Line, a high-voltage DC electrical line that brings power directly from coal-fired power plants in central North Dakota. The line was built in 1977 by the MInnkota Power Cooperative and Minnesota Power. It is one of two connecting North Dakota plants to Minnesota, and is one of just a few long distance DC transmission lines in the USA, which are used to connect remote power sources directly with urban areas, with no stops in between. The other end of the line is at the Milton. R. Young power plant in Center, North Dakota.