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.

In less than a year, Shoshone County contained additional settlements at Lewiston, Elk City, Newsome, and Florence.

The county's population dwindled as prospectors abandoned Pierce for gold prospects at Elk City and Florence.

The vast distance and time required for travel to Wallace from the Clearwater River area prompted the southern portion to move to Nez Perce County.

Hard rock miners in Shoshone County protested wage cuts with a strike in 1892.

After several died in a shooting war provoked by discovery of a company spy, the U.S. Army forced an end to the strike.

Hostilities erupted once again in 1899 when, in response to the company firing seventeen men for joining the union, the miners dynamited the Bunker Hill & Sullivan mill.

Again, people died, and the U.S. Army intervened, requested by Governor Frank Steunenberg, as the Idaho National Guard troops were still stationed in the Philippines following the Spanish–American War.

Steunenberg was assassinated outside his residence in Caldwell in 1905, nearly five years after leaving office, and the subsequent trials in Boise in 1907 made national headlines.

As of the 2010 United States Census, there were 12,765 people, 5,605 households, and 3,511 families living in the county.

[21] Shoshone County was historically a Democratic-leaning county, but has in recent years consistently voted for Republican presidential candidates, while favoring Democratic candidates locally and statewide.

School districts include:[23] It is in the catchment area, but not the taxation zone, for North Idaho College.