Minco is a city in Grady County, Oklahoma, United States. The population was 1,500 at the 2020 census, a 8.1% decrease from 2010. Present …Minco is a city in Grady County, Oklahoma, United States. The population was 1,500 at the 2020 census, a 8.1% decrease from 2010. Present-day Minco began as a settlement named Silver City on the Chisholm Trail. The community was initially a collection of tents housing Caddo, Wichita, Kiowa, and Comanche tribesmen. It was approximately 7 miles east of the present-day location. After the Rock Island extended its railroad track to the Chisholm Trail, the town physically moved to the end of the rail line and renamed itself Minco.