Grant is an unincorporated community and a U.S. Post Office in Park County, Colorado, United States. The community is located in foothills of the Front Range in the upper valley of the North Fork South Platte River, approximately 6 miles east of Kenosha Pass. It sits along U.S. Route 285 approximately 40 miles southwest of Denver. It consists largely of a r…Grant is an unincorporated community and a U.S. Post Office in Park County, Colorado, United States. The community is located in foothills of the Front Range in the upper valley of the North Fork South Platte River, approximately 6 miles east of Kenosha Pass. It sits along U.S. Route 285 approximately 40 miles southwest of Denver. It consists largely of a retired general store, post office, and surrounding houses and trailers along the south side of the highway and along the north side of the river. The Grant Post Office has the ZIP Code 80448. Grant is located at the mouth of Geneva Creek where it descends southward from the Front Range. County Road 62 follows the creek northward to Guanella Pass, leading to Georgetown in the canyon of Clear Creek.