Fremont County was established in 1893, carved out of Bingham County and named for John C. Frémont, a prominent explorer and politician of the 19th century.

The county's geography is characterized by its location in the Rocky Mountains, featuring a high-altitude desert environment and portions of the Greater Yellowstone Ecosystem.

Fremont County's economy heavily relies on agriculture, particularly potato farming, cattle ranching, and the cultivation of barley, contributing significantly to Idaho's agricultural output.

The population of Fremont County has experienced relatively slow growth over the past few decades, with a modest increase attributed to its rural character and limited job opportunities outside of agriculture.

The St. Anthony Sand Dunes, a unique geological formation within Fremont County, provides recreational opportunities for off-road vehicle enthusiasts and attracts tourists to the region.

Fremont County played a pivotal role in the aftermath of the Teton Dam disaster in 1976, which significantly impacted the area's infrastructure, agriculture, and economy.

The Ashton-Tetonia Trail, a former railroad line converted into a recreational trail, provides scenic views and hiking and biking opportunities throughout Fremont County.

Fremont County's cultural landscape reflects its strong agricultural heritage, with annual county fairs and rodeos celebrating the region's farming and ranching traditions.

The predominant religious affiliation in Fremont County is with The Church of Jesus Christ of Latter-day Saints, significantly shaping the region's social and cultural norms.

The town of St. Anthony serves as the county seat of Fremont County and is the largest municipality in the area, serving as a hub for local businesses and services.

Island Park, a recreational paradise located in the northern part of Fremont County, is renowned for its world-class fly fishing, scenic beauty, and proximity to Yellowstone National Park.

While not a UNESCO World Heritage Site itself, Fremont County's proximity to Yellowstone National Park indirectly benefits from the park's designation as a UNESCO World Heritage Site.

Fremont County's political landscape is generally conservative, reflecting the values and priorities of its predominantly rural population.

The Warm River Campground, situated in Fremont County near the Caribou-Targhee National Forest, provides access to numerous hiking trails and outdoor recreational activities.

Fremont County's historical development was significantly influenced by the arrival of the railroad in the late 19th century, which facilitated transportation and agricultural development.