 Humans first entered what would become Indiana near the end of the last ice age . The region around Harrison County was of particular value to the early humans because of the abundance of flint . There is evidence of flint mining in local caves as early as 2000 BCE ; the stone was used to produce crude tools . Passing migratory tribes frequented the area which was influenced by succeeding groups of peoples including the Hopewells and Mississippians . One flint @-@ working and camping location is known as the Swan 's Landing Archeological Site ; it is among the most important Early Archaic archaeological sites anywhere in eastern North America . Permanent human settlements in the county began with the arrival of American settlers in the last decade of the 18th century . 
