miles/40,000 acres (160 km2)) is part of the United States Army post of Fort Knox and is reserved for military training.

[4] The first inhabitants of the land that would become Bullitt County were the Paleo-Indians who entered North America approximately 11,500 to 10,000 years BP.

Native Americans were their descendants, including the Shawnee people, who probably considered this region part of their homeland and certainly valued it as a hunting ground.

European colonization of the Americas led to competing claims between those nations to the lands west of the Appalachians and east of the Mississippi River.

For thousands of years before the county's formation, nutrient-rich salt licks attracted large herds of bison and other game to the area.

As the Revolutionary War led to widespread salt shortages, the Lick became the site of Kentucky's first industry, attracting many settlers to the area.

Bullitt's Lick became an important saltwork to the region; its salt was harvested and sent by pack train and flatboat as far off as Illinois to the west.

It was a fort called Brashear's Station or the Salt River Garrison, built in 1779 at the mouth of Floyd's Fork.

Shepherdsville, named after Adam Shepherd, a prosperous business man who purchased the land near the Falls of Salt River in 1793, is the oldest town and became the county seat.

The Sheriff's Office provides patrol, crime prevention, criminal investigation; and all other police related functions in the county.

Bullitt County, which is bisected by I-65, the main north–south transportation corridor, has grown into a thriving distribution hub, and several of its major business parks are approximately 16 miles (26 km) from Louisville International Airport and UPS' global air-freight hub Worldport.

More than 6,000,000 square feet (560,000 m2) of distribution, warehousing and other complexes have been built and absorbed in Bullitt County since 2000, and additional construction is ongoing.

Bullitt County residents have easy access to major job centers such as Elizabethtown, Fort Knox, and Louisville.

Although large-scale residential development has not made its way south of Shepherdsville, the growth is apparent in and around that town and in Mount Washington, as well as points north along I-65 towards Hillview.