History of Idaho Falls Idaho begins with a wooden toll bridge across a narrow lava gorge. Freighter Matt Taylor built that bridge over the Snake River in 1865. His crossing replaced a slower ferry used by miners heading toward Montana. Bonneville County’s future seat grew up around Taylor’s bridge along the river. Because that crossing controlled regional travel, Idaho Falls grew from a stage stop into a major eastern Idaho city.
James Madison “Matt” Taylor freighted supplies toward Montana’s gold fields during the 1860s. He measured a narrow canyon on the Snake River using a stone tied to string. Taylor found the gorge just eighty-three feet wide at that point. He completed a wooden toll bridge across the site in 1865. A bank, hotel, and stage station soon appeared beside Taylor’s new bridge.
An isolated basalt island near the bridge hosted roughly twenty nesting eagles. Postal records show the settlement using the name Eagle Rock by 1866. Officials incorporated Eagle Rock as a city in 1879. Farmers meanwhile began establishing water rights along nearby Willow Creek. Growth remained modest until a major railroad reached the settlement.
The Utah and Northern Railway reached Eagle Rock in late 1878. Construction crews quickly turned the quiet stage stop into a chaotic boomtown. Workers built repair shops and yards to service passing trains. A new iron railroad bridge replaced Taylor’s original wooden structure in 1879. The railroad connected Eagle Rock to copper mines in Butte, Montana.
The Oregon Short Line Railroad reached the region in 1887. Company officials then moved most railroad shops to nearby Pocatello. Eagle Rock’s population dropped sharply once those jobs disappeared. Local leaders searched for ways to revive their struggling town. They eventually settled on a bold rebranding strategy.
Promoters worried that Eagle Rock discouraged farmers from settling nearby. They proposed a new name referencing rapids below the old bridge. Residents voted to approve the change on August 26, 1891. The city became Idaho Falls, despite having no true waterfall yet. Later dam construction eventually created the falls the name had promised.
Farmers needed reliable irrigation to succeed in this arid river valley. Builders completed the Great Feeder Canal near Ririe in 1895. At the time, it ranked as the world’s largest irrigation canal. The canal converted thousands of desert acres into productive farmland. Sugar beets, potatoes, and grain soon became the region’s leading crops.
Idaho Falls became the state’s first city with an electric power plant in 1900. Engineers installed a generator directly on an existing irrigation canal. The arrangement gave residents an early and affordable source of electricity. A larger municipal hydroelectric station followed in 1911. Idaho Falls Power still draws electricity from the Snake River today.
Idaho’s legislature created Bonneville County on February 7, 1911. Lawmakers named the county after explorer and fur trapper Benjamin Bonneville. Idaho Falls became the seat of this newly formed county. Construction on Idaho’s first Latter-day Saint temple began in the city in 1939. Church President George Albert Smith dedicated the finished temple on September 23, 1945.
The federal government established the National Reactor Testing Station near Idaho Falls in 1949. Scientists there activated Experimental Breeder Reactor I on August 24, 1951. On December 20, the reactor lit four light bulbs using nuclear energy. It marked the first time atomic power had produced usable electricity. The testing station eventually grew into today’s Idaho National Laboratory.
Idaho Falls grew from a single toll bridge into a regional hub. Railroads first built the town, then just as quickly abandoned it. A hopeful name change and new irrigation canals revived its fortunes. Hydroelectric power and nuclear research later defined its modern economy. Today, that same river still powers daily life throughout Idaho Falls.