Gem County, Idaho Gem County, Idaho Gem County is a county in the U.S. state of Idaho. As of the 2010 census, the population was 16,719. The county seat and largest city is Emmett. Gem County is part of the Boise, ID Metropolitan Statistical Area. Gem County is home to the Idaho ground squirrel. Named for the state nickname, "Gem State," the county was established on March 15, 1915, partitioned from Canyon County and Boise County. Fur trappers were in the area as early as 1818, and Alexander Ross explored Squaw Creek in 1824. Prospectors and miners moved through the county in 1862
Secondary state highways as branches of Primary State Highway 7 (Washington) 10/PSH 18 in Moses Lake northeast to PSH 7 west of Odessa. The only part of this route that was ever constructed and signed as SSH 7E was a road through Moses Lake from US 10 (later Interstate 90)/PSH 18 in the southwest to SSR 11G in the northeast. Today, this route is SR 171. The leg from SSR 11G (today's SR 17) to the Odessa area has never been constructed and is not part of the modern state route system. Secondary state highways as branches of Primary State Highway 7 (Washington) Between 1937 and 1964, the highway system in