The Snake River that runs through Idaho played a crucial role in the development of the state. The river was used to transport goods and supplies, and it was also used to generate hydroelectric power, which helped to fuel the state's growth and development.
Jefferson County, Idaho, has a rich and diverse history that dates back thousands of years. The region was originally inhabited by Native American tribes such as the Shoshone and Bannock, who relied on hunting, gathering, and fishing to sustain their communities. Their presence in the area would shape the region's future as European settlers arrived.

The arrival of European explorers and fur trappers in the early 19th century marked a new era for Jefferson County. The Lewis and Clark Expedition, led by Meriwether Lewis and William Clark, passed through the area in 1805, documenting their journey and mapping the land. This opened the door for future settlers and led to increased exploration and settlement in the region.

By the mid-1800s, pioneers began to establish permanent settlements in Jefferson County. The Oregon Trail, a major westward migration route, passed through the area, attracting settlers in search of new opportunities. Over time, farming and ranching became the main economic activities in the region, with communities like Rigby and Menan prospering as agricultural centers.

The 20th century brought significant changes to Jefferson County. The construction of the Minidoka Dam in the 1900s brought irrigation water to the area, transforming dry lands into fertile farmland. The development of transportation infrastructure, such as roads and railways, further connected the county with the rest of the state and facilitated economic growth. Today, Jefferson County retains its agricultural heritage while also benefiting from its proximity to larger cities like Idaho Falls, contributing to the county's ongoing development and prosperity.

This timeline provides a glimpse into the major events and milestones that have shaped the history of Jefferson County, Idaho.

  • 1810: Lewis and Clark expedition passes through the area
  • 1833: Fur trader and explorer Benjamin Bonneville explores the region
  • 1863: Jefferson County is established as a county in Idaho Territory
  • 1882: First railroad, the Utah & Northern, reaches the county
  • 1889: Idaho becomes the 43rd state, including Jefferson County
  • 1923: Snake River electrification project brings electricity to the county
  • 1949: Idaho National Laboratory (INL) is established in the county
  • 1972: Accident at the INL's SL-1 nuclear reactor results in fatalities
  • 1981: The Jefferson County Historical Society is founded
  • 2000: County population surpasses 20,000
  • 2016: Jefferson County celebrates its 150th anniversary