Hardin was established in 1907 by Carl Rankin, an agent of the Lincoln Land Company. He sold the first piece of land for about $106.25 to Thomas Mullet and Henry E. Clifford. At the time that place was named Ft. Custer then later the name was changed to Hardin. Carl Rankin named the town after his friend Samuel Hardin, a rancher and early settler who lived south of Hardin, in Ranchester, Wyoming.
As one of the last areas in the Montana plains to be settled, Hardin was originally set up by the Lincoln Land Company as a trading spot alongside the railroad. Hardin was named Bighorn County seat in 1913, and by 1922 the town was well established with a developed business district.
Ranching and farming are still popular in this area today. Hardin is a great base camp for The Little Bighorn Battlefield, visits to Bighorn Canyon National Recreation Area and the many other area activities and sites. Little Bighorn Days is a four-day festival that takes place every year towards the end of July, featuring Custer's Last Stand Re-enactment which is based on Crow Tribal Elder Joseph Medicine Crow’s translation of Native American writings and talks dating back 200 years ago. With a staged battle occurring in nearby plains, visitors can see a first-hand account of what the battle was like. The festival also features ethnic food and wonderful performances.