Twin Falls County
There are 8 US Post Offices in Twin Falls County serving a total of 129,222 residents equating to 16,153 residents per post office. It's estimated that approximately 206,253 packages are handled across the 8 county post offices annually. Twin Falls County is a county in the south central part of the U.S. state of Idaho. As of the 2010 Census, the county had a population of 77,230. The county seat and largest city is Twin Falls. Twin Falls County is part of the Twin Falls, ID Micropolitan Statistical Area. Prior to the 1860s, the Twin Falls County area was an unorganized part of Shoshone lands, then as part of the Oregon Country. The area was first organized as part of the original Owyhee County in 1864 as part of Idaho Territory. In 1879 it was partitioned away from Owyhee County to form part of Cassia County. The county is named for a split waterfall on the Snake River of the same name. The Snake River is the county's northern boundary. Even after Idaho became a state in 1890, the Twin Falls area was very sparsely populated and without significant settlements. That changed after the city of Twin Falls was founded in 1904 and Milner Dam was completed in 1905. Most of the county's other towns were established during this period as well. In response to local government needs for these new communities, which were as much as 80 miles (130 km) away from Cassia County's seat at Albion, Twin Falls County was created by the Idaho Legislature on February 21, 1907."