Northern States Power Company's timeline begins with the organization of the Washington County Light & Power Co. in 1909. When H. M. Byllesby began building his utility holding company across the Northwestern region of the US, he renamed it the Consumers Power Co. in 1910 and which was renamed the Northern States Power Co. in 1916. While the bulk of NSP's territory grew across central and southern Minnesota (starting from the Twin Cities), it acquired territory in North Dakota (centering on Fargo, Grand Forks, and Minot) and extended southwest into South Dakota (centering on Sioux Falls). NSP's system also extended east into Wisconsin, but because of utility ownership laws in that state, it was operated as an entity separate from the rest of the company.