The former Southern line from Louisville trails into the former CNO&TP line from Lexington and Cincinnati from the northwest at SJ Tower, just south of Faulconer. The CNO&TP line continues south, past DV Tower, into Danville, where the depot is on the east side of the line and the Danville Yard on the west side, turning southwest with double track at South Danville, and then south again, past detectors at MP 120.8, through moderate hills with gentle curves, to Junction City, where an east-west L&N line once crossed at grade. At Bowen (MP 122.x), where single track starts, the line edges south-southwest, and then south again past Moreland, turning southeast past a detector at MP 128.7, Palms (MP 130.2), where it turns south-southeast and double track starts again, McKinney, Geneva, where it turns south, South Fork (MP 134.8), where it turns south-southeast again, Sunrise Creek Trestle, a detector at MP 138.9 on a single track section of line relocated away from some former tunnels, and King's Mountain, where a Cincinnati & Kentucky Southern line once trailed in on the west side and double track starts again at MP 139.2.
The line heads just east of due south, with, past Waynesburg (MP 142.1), Eubank, Gradison, Pulaski, a detector at MP 157.8 on a curvy section, Science Hill and Norwood into Somerset (MP 160.x), where the line is briefly headed south-southeast. Continuing south, the line passes Woods (Ferguson Shops), detectors at MP 163.1, and Elihu, turning south-southwest past grove and then south-southeast past Burnside (MP 167.x) and across the long bridge over an arm of Lake Cumberland, turning south again past Tateville, where a lengthy single-track 1963 relocation, away from a more easterly segment through four erstwhile tunnels and Sloans Valley, begins, curving south-southeast and then south again, through deep cuts with road bridges overhead at Cave Springs Road, ??, and Sheldon Road, past a detector at MP 175.5, and then east past KD Tower (MP 177.5), where double track starts again, to the end of the relocation at Greenwood, where it turns south again to Cumberland Falls.
Another single track 1963 relocation bypasses two more tunnels on a segment further east than the relocated line, which passes a detector at MP 188.3 before the end of the relocation at Flat Rock, and thence south past Marsh and Whitley (MP 190.4), where double track starts again, to Stearns (MP 192.5). Here, the former Kentucky & Tennessee heads away to the west while the main line turns south-southeast past Revilo, south at Pine Knot past Silerville and a detector at MP 201.1 and across the Kentucky-Tennessee state line to Ratliff, south-southwest past Winfield, west past Bear Creek, and southwest to Oneida (MP 209.4), where the Onedia & Western once headed west, and the former Tennessee Railroad, now an NS branch line, still heads away south.
The "Rathole" continues southwest, past crossovers at Pemberton (MP 211.5), aka "High Point", the highest point on the Rathole, and detectors at MP 211.8, and then turns south, to Helendale, where it turns south-southwest, and Phillips (MP 215.4), where a branch that once formed the main line heads south while the single track post-1963 main line, taking a more westerly course across the massive steel deck truss, with concrete piers, New River Bridge at MP 218, later turns west-southwest before turning south again past Robbins (MP 222), where the pre-1963 routing trails in on the east side, and then curvily south-southwest past Rugby Road, Glen Mary, detectors at MP 226.0, and Huffman. a further 1963 relocation takes the line south, where it had once continued south-southwest, and then southwest to Sunbright, end of the relocation, where it turns south, double track once again, past detectors at 234.9, and then curvily south past Annadel, and southeast and then south-southwest past Lancing, where the Emory River Railroad once trailed in from the east and there is a coal loader.
The main line turns curvily southeast at detectors at MP 241.8, past CW Tower where single track starts, southwest through Tunnel 23 to Nemo (MP 243), in the Emory River Gorge, where the Morgan & Fentress Railway once headed west, south through 2700 ft. Tunnel 24, southeast past Coleman, and curvily south past Camp Austin, a detector at MP 251.3, North Oakdale, where double track begins again and the yard on the west side of the line begins, Oakdale (MP 254), where the 3' gauge Waldens Ridge Railroad once headed east and the main line turns southwest (MP 254.8), single track once again, Tunnels 25 & 26, and south to Harriman Junction (MP 258.2), where the single track line to Knoxville turns away east and the double track main line to Chattanooga continues south.