Beaver County, Utah
In 1776 the Dominguez-Escalante expedition crossed the county near present Milford. Jedediah S. Smith (1826-27) and John C. Fremont (1844) had also traveled in the Beaver area. Parley P. Pratt and his exploring expedition passed through in January 1850; Pratt wrote "This is an excellent place for an extensive Settlement."
But it took another six years for settlers to move in. The Territorial legislature created Beaver County in January 1856, and the first group of settlers moved to the new county in February.
source: Utah State History. Online. 2014 Accessed March 12, 2015.