Submitted by yongli on Fri, 03/31/2017 - 16:35 Share to Jefferson County, popularly known as "Jeffco," lies west of Denver. It was established in 1861 as one of the original seventeen counties of the Colorado Territory. Image by: Benbennick, DavidSource: Jefferson County, Colorado - WikipediaCopyright Notes: Image courtesy of Wikimedia Commons.
