No significant development took place until 1864, when a man named Harry Rickets built and operated a ferry on the Snake River at 43°36.112′N 112°3.528′W / 43.601867°N 112.058800°W / 43.601867; -112.058800.

The ferry served a new tide of westward migration and travel on the Montana Trail following the Bear River Massacre of Shoshone Indians in 1863.

[7][8] The present-day site of Idaho Falls became a permanent settlement when freighter Matt Taylor built a timber-frame toll bridge across a narrow black basaltic gorge of the river 7 miles (11 km) downstream from the ferry.

The bridge improved travel for settlers moving north and west, and for miners, freighters, and others seeking riches in the gold fields of Idaho and Montana –especially the boom towns of Bannack and Virginia City.

By the end of 1865, a private bank, small hotel, livery stable, eating house, post office, and stage station had sprung up near the bridge.

The name was derived from an isolated basalt island in the river near the ferry, where approximately twenty eagles nested.

The U&NR had the backing of robber baron Jay Gould, as Union Pacific Railroad had purchased it a few years prior.

The railroad company had 16 locomotives and 300 train cars working between Logan, Utah and the once-quiet stage stop.

A new iron railroad bridge was fabricated in Athens, Pennsylvania at a cost of $30,000 and shipped by rail to the site, where it was erected in April and May 1879.

The camp-town moved on, but Eagle Rock now had regular train service and several U&NR buildings, shops, and facilities which expanded and transformed the town.

[12] Large-scale settlement ensued and within a decade, there appeared roads, bridges, and dams, which brought most of the Upper Snake River Valley under cultivation.

In 1891, marketers convinced town leaders to change the name to Idaho Falls in reference to the rapids below the bridge.

On June 22, 1895, the world's then-largest irrigation canal, the Great Feeder (located 5 miles northeast of Ririe), began diverting water from the Snake River, helping to convert tens of thousands of more acres of desert into green farmland.

The area grew sugar beets, potatoes, peas, grains, and alfalfa, and became one of the most productive agricultural regions of the United States.

In 1949, the Atomic Energy Commission opened the National Reactor Testing Station (NRTS) in the desert west of Idaho Falls.

Three trained military men had been working inside the reactor room when a mistake was made while reattaching a control rod to its motor assembly.

[13] With the central control rod nearly fully extended, the nuclear reactor rated at 3 MW rapidly increased power to 20 GW.

[14][15] As the steam expanded, a pressure wave of water forcefully struck the top of the reactor vessel, upon which two of the men stood.

The explosion was so severe that the reactor vessel was propelled nine feet into the air, striking the ceiling before settling back into its original position.

[16][17][18] The core meltdown caused no damage to the area, although some radioactive nuclear fission products were released into the atmosphere.

The community's economy was mostly agriculturally focused until the opening of the National Reactor Testing Station in the desert west of Idaho Falls in 1949.

The city subsequently became largely dependent on high-income jobs from the Idaho National Laboratory (INL), known locally simply as "The Site."

Today, it is home to a handful of locally owned shops, stores, restaurants, galleries, theaters, and future revitalization efforts.

Each year, after the game, the winning team and its fans traditionally paint the goalposts of the stadium in their school colors (orange for Idaho Falls and blue for Skyline).

There are four major news outlets in the area: KIDK (Dabl, also broadcast on sister Fox station KXPI-LD), KIFI-TV (ABC/CBS), KPVI-DT (NBC, licensed to Pocatello), and Idaho Public Television.