The Lemhi County Historical Society and Museum located in Salmon, Idaho is the go-to place for education on the history of Lemhi County. Although Meriwether Lewis and William Clark passed through the area in 1805 on their trek westward, Fort Lemhi was established in 1855 by a group of Mormon missionaries. They abandoned the fort in 1858 due to conflicts with the Nez Perce Nation. Lemhi County itself was established in 1869.

Lemhi County Historical Society was originally founded in the early 20th century to document the lives of early Lemhi County settlers. The Society was inactive between 1928 and 1956, at which point it reformed and began to grow its collection of artifacts. In 1963, the Lemhi County Museum was opened to display the series of items that had been collected over the course of decades.

The museum contains a variety of historical exhibits centering around Salmon City and Lemhi County and is open year-round.