Washington County, Colorado: History
Colorado State Legislature made Washington County out of larger Weld County in 1887. In 1889, Washington County's eastern half formed Yuma County. In 1903, Arapahoe County ceded its eastern portion to Washington County to create its present form.
Like many counties in Eastern Colorado, The Great Depression affected Washington County, bringing its population down significantly. Recently growth has been stagnant.
Washington County's Eastern Colorado Roundup is home to Colorado's first home-owned carnival held on every July annually. There are activities such as rodeos, various rides, and animals to see.