Kentucky Route 70 is a long east-east state highway that originates at a junction with US 60 in Smithland in Livingston County, just east of the Ohio River. The route continues through the counties of Crittenden, Caldwell, Hopkins, Muhlenberg, Butler, Edmonson, Barren, Barren, Metcalfe, Green, Taylor, Casey, Pulaski, Lincoln and back into Pulaski again to terminate at a junction with U.S. 150 near Maretburg in Rockcastle.

The low underpass under railroad tracks near Eubank KY has been closed and bypassed with a highway overpass just north of old route. The new roadway is wider and has no restrictions.

KY 70 does not connect between Tiline and Dycusburg. Previous ferry service has been discontinued for a number of years.

KY 70 includes concurrent designations with these routes:

KY 70 is the main route through Mammoth Cave National Park in Barren and Edmonson counties. Improvments completed in Liberty in early 2013 to widen KY70 from near Green River bridge, to Connector Road, as part of the Dry Ridge Hill reconstruction project. Future plans include major upgrades further east past High School with improvments ending near KY501. Reconstruction of KY70 west of Liberty from KY1547 to KY206 area near Creston. Further plans would create a more direct route for KY70 to connect Liberty to Campbellsville.

There is a low clearance on KY 70. It is in the town of Eubank and is 1.2 miles (1.9 km) West of US 27.