From there, the route traverses LaRue, Hardin and Bullitt counties to terminate in Jefferson County (where it is commonly signed as Preston Street or Preston Highway) at the junction of U.S. Route 31E (East Main Street) in downtown Louisville.

The first 12.8 miles (20.6 km) of KY 61 is considered part of the Appalachian Development Highway System’s Corridor J project.

[4] KY 61 goes on a northwestward course to Green and LaRue counties, traversing Greensburg and Hodgenville, respectively.

At Hodgenville, KY 61 continues northwest into Hardin County to the US 31W and Wendell H. Ford Western Kentucky Parkway junction in Elizabethtown, and runs concurrently with the northbound lanes of the U.S. route there.

In downtown Elizabethtown, KY 61 begins a concurrency with US 62 from there through the I-65 Exit 94 interchange, all the way to just past Boston, in western Nelson County.