Fremont County, Idaho: History
Fremont County was established in 1893 when Bingham County was partitioned. It is named for John C. Frémont.
The county initially contained all of the northern portion of eastern Idaho north of Bonneville County. The counties of Jefferson and Madison were created from Fremont in 1913. Teton County was later created from Madison in 1915 and a portion of Butte was created from Jefferson in 1917. Clark County was also created from Fremont in 1919.
The first fur trapping operation by a United States fur company west of the Rocky Mountains occurred in 1810 when Andrew Henry established a fort in the fall of 1810 on Conant Creek in southern Fremont County. Henry later moved the fort to the south bank of the Henry's Fork of the Snake River between present-day settlements of Salem and Parker. The fort was abandoned some time after 1811.
At the time of early settlement, Fremont County was located on the northern edge of Oneida County. Mining, timber, and ranching operations commenced in the Island Park area prior to 1870. The establishment of Yellowstone National Park in 1872 also contributed to the eventual development of the Island Park area as a popular recreation area. Construction of the Egin Canal commenced in 1879 and farming settlement of the Egin area followed. In 1883, Parker was established and settlement commenced at Teton. These settlements became part of Bingham County when it was created in 1885. Settlement at St. Anthony started in 1888 while the Ashton area settlement of Marysville commenced settlement in 1889. At the 1890 Census, Bingham County enumerated 301 residents in the precincts of Teton and Henry's Lake.
Additional settlement occurred at Warm River in 1896, the Drummond area in 1900, and Newdale in 1914.
The Fremont County Courthouse in St. Anthony is on the National Register of Historic Places.