Kentucky Route 255

Kentucky Route 255 (KY 255) is a 16.977 mi south-north state highway located in south central Kentucky. It provides access to Interstate 65 and Mammoth Cave National park to residents of southern Barren County.

Rocky Hill to Park City
KY 255 begins at a junction with KY 252 in Barren County, near the Rocky Hill community. The route is narrow and considerably curvy until coming to a junction with KY 1297 about 3.3 mi later. After this junction, the route straightens somewhat, proceeding north for another 3.1 mi before coming to an intersection with the concurrently running US 68/KY 80 in the Bon Ayr community.

KY 255 widens somewhat past this point, continuing on for another mile before bridging the Louie B. Nunn Cumberland Parkway via way of an overpass. The route then proceeds north for 0.8 mi before coming to an intersection with KY 1339.

KY 255 then continues north for 2.5 mi before being carried onto a bridge over a CSX railroad track, the Louisville and Nashville Railroad before intersecting U.S. Route 31W. KY 255 previously passed the ruins of Bells Tavern, and then intersected US 31W (Second Street) after a railroad crossing until 2012, when it was re-routed to go over the tracks via a new bridge on the west side of town. KY 255's concurrency with US 31W lasts 0.16 mi, where KY 255 turns left onto Mammoth Cave Parkway. Its original concurrency with US 31W lasted for 0.2 mi.

Mammoth Cave National Park and northwestern Barren County
After its brief concurrency with US 31W, KY 255 branches north, going 0.4 mi before intersecting with Interstate 65 (I-65) at its Exit 48 interchange. After this intersection, KY 255 continues in a northwesterly path and enters Mammoth Cave National Park; the southern entrance of the park is approximately 0.4 mi north of the Interstate. It proceeds north for another 0.9 miles, passing Diamond Caverns before entering the far eastern portion of Edmonson County and reaching its first intersection with KY 70 in the southern part of the park near the site of a former town named Chaumont. This was KY 255's original northern terminus from the 1930s until sometime in the mid-1970s. At that point, KY 255 joins KY 70 by making a right turn eastward to re-enter Barren County. This concurrency lasts for 1.666 mi before reaching an intersection in Highland Springs, where KY 255 turns left, while KY 70 turns right to head for Cave City. KY 255's current northern terminus is located near the Sand Cave Trail at the southeastern entrance into the Mammoth Cave National Park; that point marks the end of state maintenance. The road itself, however continues into the park solely as Cave City Road, and ends at another intersection with the Mammoth Cave Parkway just south of the park's visitor center. This road was part of the original KY 70 alignment within the park until it was rerouted to its current in-park alignment in the 1970s.

KY 255's final 1.259 mi segment between Highland Springs and the northern terminus is part of the Cordell Hull Scenic Highway, part of the Kentucky Scenic Byways system.

History
The state route was established during the 1930s. it originally ran from Park City northward to closely follow and cross the Barren-Edmonson County line on its way to Chaumont, and then eastward into Barren County to end where the current eastern split of KY 255 and KY 70 is located. In the 1950s, the KY 255 designation was extended southward onto a few formerly locally maintained back roads to Bon Ayr (formerly Bonayer), and further south to KY 252 at Game (now Rocky Hill) just north of the Barren River shortly before that segment of the river was impounded to form Barren River Lake. KY 255 was also extended onto the old KY 70 alignment from the current KY 255/70 split in Barren County to the southeast boundary of the Mammoth Cave National Park.

In 1991, the segment of KY 255 from the I-65 interchange at Park City to the KY 70 junction at Chaumont was transferred to the National Park Service for that stretch of roadway to become a new portion of Mammoth Cave National Park.

Points of interest
The ruins of Bells Tavern are located alongside the original KY 255 alignment near the railroad tracks. Built in 1830, it was a favorite stop of wealthy patrons before it burned in 1860. A roadside marker marks the location of the tavern and details some of its history.

Diamond Caverns, the second oldest cave tour operation in the United States, is located just off of KY 255, just north of its intersection with I-65. A roadside marker gives a history of the site.