Idaho

The name Idaho has one of the most controversial and uncertain etymologies of any U.S. state. In the early 1860s, when Congress was considering names for a new territory in the Rocky Mountains, lobbyist George M. Willing proposed "Idaho," claiming it was a Shoshone phrase meaning "gem of the mountains" or "the sun comes from the mountains." This romantic explanation was widely promoted and believed.

However, later research revealed that Willing had fabricated this etymology—no such word existed in Shoshone or any other Native American language of the region. By the time this deception was discovered, the name had already gained popularity from its use in "Idaho Territory" (originally proposed for what became Colorado) and through the Pike's Peak gold rush region. Despite knowing it was invented, territorial authorities decided to keep the name.

Several alternative theories have been proposed for the name's true origin. Some linguists suggest it might derive from the Kiowa-Apache term ídaahę́, though this connection is tenuous. Others propose it could be a corruption of "Ee-dah-how," a purported Shoshone greeting, though this too lacks solid evidence. A third theory suggests Willing may have created a pseudo-Native American-sounding name by combining syllables he found aesthetically pleasing.

The Idaho Territory was officially created on March 4, 1863, encompassing present-day Idaho, Montana, and most of Wyoming. After Montana and Wyoming territories were split off, Idaho achieved statehood as the 43rd state on July 3, 1890. Despite its dubious origins, the name has become beloved, embraced by residents who often proudly reference the "gem of the mountains" phrase—even while acknowledging its fictional status.

The demonym Idahoan follows standard English demonym formation, adding the -an suffix to create a descriptor for the state's residents. This straightforward suffix pattern contrasts ironically with the mysterious and invented nature of the state's name itself.