Muldraugh Hill is an escarpment in central Kentucky separating the Bluegrass on the north and north-east from the Pennyrile on the south and south-west. This escarpment fades into the Pottsville Escarpment on the east, and terminates at the Ohio River in the west, although in truth it continues in Indiana as Floyd Knobs.
In parts of its eastern stretches, Muldraugh Hill is little more than a slight hill, but in some of the western areas, it's represented by extensive areas of knobs. The formation comprises mostly siltstones and shales, with some minor limestones, between the limestones and dolomites of the older Bluegrass and the limestones of the newer Pennyrile. Rock outcrops are minor except where the overlying limestones are exposed in the north end of Fort Knox.
The western part of the county is in the area of rugged topography of the Knobs and dissected upland behind MuldraughHill (Highland Rim escarpment).
MuldraughHill, an east-facing cuesta, and the isolated round hills or knobs carved from this upland are the most conspicuous topographic features of Bullitt County and contain both the highest elevations and the sites of greatest local relief.
The hills and ridges at the eastern edge of MuldraughHill may attain elevations in excess of 900 feet.
Muldraugh was named after MuldraughHill, a dominant ridge just east of the city which stretches from West Point in Hardin County, on the Ohio River; 75 miles southeasterly through Nelson and LaRue Counties to Calvalry in Marion County.
The Muldraugh Post Office was established in 1874, and Muldraugh was incorporated in 1952.
Muldraugh began as a small settlement between Louisville and Nashville; it grew in size after the Fort Knox Military Reservation was established in 1918.