Shoshone County shə-SHOHN is a county in the U.S. state of Idaho. As of the 2020 census, the population was 13,169. The county seat is Wallace and the largest city is Kellogg. The county was established in 1864, named for the Native American Shoshone tribe. Shoshone County is commonly referred to as the Silver Valley, due to its century-old mining history. The Silver Valley is famous nationwide for the vast amounts of silver, lead, and zinc mined from it.