[2] It travels eastward to a junction with KY 866, and reaches a dead end at Tiline, along the Cumberland River.

[11][12] KY 70 leaves the US 431 concurrency at that point south of Drakesboro, and provides a scenic drive from there, past the old site of the Rochester Dam before crossing the Mud River into Butler County.

Until 2021, steam from the Tennessee Valley Authority's Paradise Coal-firing plant can be seen from the highway between Drakesboro and Rochester.

It then intersects Kentucky Route 106 (KY 106/Huntsville-Quality Road) not too far southeast of there, and would then go on to the communities of South Hill and Dunbar.

[19][20] Going east from Brownsville, KY 70 is the main route through Mammoth Cave National Park in Edmonson County, including the site of the former town of Elko.

While traversing the park, KY 70 runs concurrently with the Mammoth Cave Parkway before entering Barren County.

[21][22][23] Most of KY 70 from Brownsville to Cave City is designated as part of an official Kentucky Scenic Byway.

After running a concurrency with a third route, KY 61, US 68/KY 70 continues east into Taylor County, where it transitions from Central into the Eastern time zone.

[30] After that KY 70 crosses the Green River for a fifth and final time, and traverses mainly rural areas of Casey, and then parts of southern Lincoln and northern Pulaski Counties.

KY 70 ends at its eastern terminus at a junction with US 150 near the Rockcastle County community of Broadhead, just west of Mount Vernon.

[41][42][43] A 1950 highway planning survey conducted by the Kentucky Department of Highways and the United States Department of Agriculture showed that the segment between KY 70's original eastern entrance to Mammoth Cave National Park and its crossing of the Louisville and Nashville Railroad in downtown Cave City was the most heavily traveled segment of the route.

[44] The low underpass under railroad tracks near Eubank just west of the US 27 junction has been closed and bypassed with a highway overpass just north of old route.

Improvements were completed in Liberty in early 2013 to widen KY 70 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 the Casey County High School with improvements ending near KY 501.