Idaho State

In the early 1860s, when the United States Congress was considering organizing a new territory in the Rocky Mountains, eccentric lobbyist George M. Willing suggested the name "Idaho", which he claimed was derived from a Shoshone language term meaning "the sun comes from the mountains" or "gem of the mountains". Willing later claimed that he had simply invented the name. Despite this lack of evidence for the origin of the name, many textbooks well into the 20th century repeated as fact Willing's account that the name "Idaho" derived from the Shoshone term "ee-da-how".

The name "Idaho" may be derived from the Plains Apache word "ídaahe´", which means "enemy." The Comanches used this word to refer to the Idaho Territory.

Mapped Location

The mapped location is an approximation and should not be used for navigation or wayfinding.


  • Feature Type: Civil
  • Capital City: City of Boise
  • Established as a Territory: Wednesday, March 4, 1863
  • Admitted to the Union: Thursday, July 3, 1890

Official, historical, colloquial and alternative spellings for Idaho

State of IdahoOfficial

Quoted remarks, origin notes and general history for Idaho

“HISTORICAL.—Until 1848 what is now Idaho was a part of the Northwest coast. From 1848 to 1853 it was a part of Oregon territory. From 1853 to 1859 all Idaho north of 46° was attached to Washington Territory, while all south of that remained in Oregon. From 1859 to 1863 ail Idaho was a part of Washington. The name Idaho was first applied in 1863 when it was formed into a territory. In 1864 Montana and in 1868 Wyoming were created out of Idaho, and in 1890 it was admitted as the forty-third state of the American Union. Oregon is Idaho's grandmother; Washington her mother; and Montana and Wyoming her daughters.”

John E. Rees, B. Sc., Idaho Chronology, Nomenclature, Bibliography
  • U.S. Board on Geographic Names. Geographic Names Post Phase I Board/Staff Revisions. 01-Jan-2000. Board decisions referenced after Phase I data compilation or staff researched non-controversial names.
  • Rees, John E., Idaho Chronology, Nomenclature, Bibliography, 1918 W.B. Conkey Company, pp. 77
  • U.S. Board on Geographic Names. BGN work cards. 31-DEC-1930.
Last edited on 12/5/2016