Download coordinates as: CU is the designation of a line for high-voltage direct current (HVDC) transmission between the Coal Creek Station power plant south of Underwood, North Dakota at 47°22′24″N 101°9′23″W / 47.37333°N 101.15639°W / 47.37333; -101.15639 (Underwood Static Inverter Plant) and the Dickinson converter station near Buffalo, Minnesota at 45°06′40″N 93°48′36″W / 45.11111°N 93.81000°W / 45.11111; -93.81000 (Dickinson Static Inverter Plant).

Great River Energy recently announced that the mine-mouth plant that supplies this line, Coal Creek Station, will be decommissioned in 2022, unless another entity steps up to acquire (and continue operating) the plant, leaving the future of this line in doubt.

The CU line, which went in service in 1978, can transfer an electrical power of 1,000 megawatts at a symmetrical transmission voltage of 400 kV.

An overhead line connection 436 miles (710 kilometers) long is used, with two conductors per pole.

This is the only crossing point of two HVDC overhead powerlines in the Western hemisphere.