Although Lewiston briefly served as Idaho's capital from the formation of Idaho Territory in 1863, the territorial legislature moved it to Boise on December 24, 1864. Construction of the first portion of the capitol building began in the summer of 1905, fifteen years after statehood.

Idaho's state seal is the only one in the U.S. designed by a woman. Emma Edwards Green entered a statewide competition for the honor in 1891 by using only her initials.

Franklin was founded by Mormon pioneers on April 14, 1860. For ten years, the city believed itself to be located in Utah, but an 1872 survey found that it was actually one mile inside the Idaho Territory border.

At 7,993 feet (2,436 m) deep, Hells Canyon in western Idaho is the deepest river gorge in North America. In comparison, the Grand Canyon is only 6,000 feet deep.

At 12,668 ft (3,861 m) Borah Peak is the highest mountain in Idaho and one of the most prominent peaks in the contiguous United States. It was unnamed until it was discovered to be higher than Hyndman Peak, previously regarded as the state's highest point. In February 1934, the U.S. Geological Survey named it for William Borah, the prominent U.S. Senator from Idaho, who had served for nearly 27 years at the time and was dean of the Senate.

Soda Springs is named for the hundreds of natural springs of carbonated water that are located in and around the city. The springs were well known to Native Americans and were a famous landmark along the Oregon Trail. Today the city is known as the location of the Soda Springs Geyser, which was unleashed in 1934 when "town fathers" were looking for hot water for a "hot pool" bathing attraction. Instead they drilled into a chamber of highly pressurized carbon dioxide gas and cold water and the geyser was released. After running for weeks, and flooding the downtown area, it was capped and manually released on request as a tourist attraction. Today, it is let loose every hour on the hour by a timed release valve.

Ernest Hemingway arrived in Sun Valley in 1939 to work on his novel, For Whom the Bell Tolls. Idaho offered wide open spaces for Hemingway to indulge in his passions for hunting, skiing, fishing, and other outdoor activities. He is buried in Ketchum, Idaho where he took his own life on July 2, 1961.

Who really invented the television? Revisionist history says RCA, but in truth it was a Mormon farm boy from Rigby, Idaho. Philo Taylor Farnsworth was just 14 when he drew up blue-prints for the first fully-functional all-electronic television system.

Thirteen U.S. states are split into two time zones, and Idaho is one of them. The state's north, the relatively isolated Idaho Panhandle, is closely linked with Eastern Washington, with which it shares the Pacific Time Zone--the rest of the state uses the Mountain Time Zone.

The largest and best western white pine (Pinus monticola) forests can be found in northern Idaho in the Coeur d'Alene and Bitterroot Mountains.