In northern Colorado, early farmers in the Poudre and Platte valleys overcame dry, crusty sod by digging hundreds of miles of irrigation canals beginning in 1870, effectively creating “more rivers” and transforming part of the Great American Desert into a powerful agricultural region. As irrigation spread, farming rivaled mining as Colorado’s primary industry, the state’s cultivated acreage increased thirty-fold between 1870 and 1920, and agriculture’s share of the economy more than doubled. The methods developed here helped give Colorado and the Great Plains a foundation for permanent settlement, and even after many mines were abandoned, the canals remained in use as the backbone of an extensive farming civilization. Weld County became one of the nation’s most heavily irrigated counties. After Benjamin Eaton dug a small ditch himself, he recognized that large-scale irrigation required settlers to combine energy, skill, and capital, since individuals could water only a few acres while groups could irrigate whole counties. In 1870 the Union Colony formed the first canal cooperative, or joint-stock company, guaranteeing each shareholder a certain amount of water per year in return for construction and maintenance fees. During the 1880s, more than a dozen similar facilities opened in northern Colorado, including Eaton’s vast Larimer and Weld Canal, which created well over 60,000 acres of new farmland.