From Frisco, TN (MP 88.2), just south of the state line, where there is an interconnection with the former Southern Railway (now NS) line south from Big Stone Gap, through Natural Tunnel, that continues many miles southwestward from Frisco, the former Clinchfield continues southeast, single track, CTC, maximum speed 40 mph, past two short tunnels, a 30 mph speed restriction through Kingsport, from MP 90.5 to MP 96.5, a turn east and then southeast again, a north-facing spur on the east side, a north-facing signal at Kingsport Holdout (MP 92.1), a 17,278 ft. west-side siding from North Kingsport (MP 93.0), where there is a north-facing spur off the siding, to South Kingsport (MP 96.5), with a 20 mph freight speed restriction, from MP 93.8 to Kingsport Scales (which are on the main only, at MP 94.1), Kingsport Yard, on both sides, where there is a south-facing spur on the east side and a crossover, and south-facing spurs on both sides, all within the siding.
The line turns curvily south at Pactolus, where it bridges over the start of the Tennessee River, with a 35 mph speed restriction, from MP 96.5 to MP 100.2, past a detector at Hemlock (MP 99.3) and the 6,330 ft. east-side siding, from North Fordtown (MP 102.8) to South Fordtown (MP 104.2), turning sharply counter-clockwise north and then sharply clockwise south, past Gray, MP 107.1, where the maximum speed rises to 45 mph, and curvily south-southeast, past the 6.097 ft. west-side siding, from North Boone (MP 111.1) to South Boone (MP 112.4), where there is a 30 mph speed restriction to MP 112.5, a short tunnel, and a detector at Indian Ridge (MP 115.2), , bridging over the former Southern line to Bristol and turning east, past the 16,983 ft. east-side siding (30 mph on the siding), from North Johnson City (MP 119.4) to South Johnson City (MP 122.9), with a north-facing spur from the siding at the north end and a south-facing spur from the siding at the south end, where the East Tennessee Railroad connects (MP 121.9), heading northeast.
There are some curves, followed by a turn south, past a wide-load detector at MP 125.5, and curvily south-southeasat, past a 35 mph speed restriction, from MP 128.4 to MP 132.3, the 6,580 ft. west-side siding, from North Hannum (MP 128.9) to South Hannum (MP 130.3), where an erstwhile narrow-gauge line once headed east, a detector at "North Erwin" (MP 131.2), a 25 mph speed restriction through Erwin, from MP 132.3 to MP 133.7, the Rock Creek Lead on the west side at Rock Creek (MP 132.3), the Erwin Terminal, from North Erwin (MP 133.7) to South Erwin, MP 138.0), with a 20 mph speed restriction from MP 133.7 to MP 140.2, and a 25 mph speed restriction, from MP 140.2 to MP 160.7, to Loves, turning south, to Chestoa, east to Unaka Springs, and curvily southeast, across the state line between Tennessee and North Carolina, past Lost Cove, where it turns curvily east.
The line turns south, past the 6,670 ft. west-side siding, from North Poplar (MP 148.1 to South Poplar (MP 149.5), east past Huntdale, where an erstwhile anrrow gauge line from Bald Mountain once 'joined' from the southwest, north, curvily east, curvily south-southeast, past a detector at Relief (MP 155.9) and the 7,007 ft. west-side siding (20 mph on the siding), from North Green Mountain (MP 159.5) to South Green Mountain (MP 160.9), very curvily east-northeast, with a 20 mph speed restriction, from MP 160.7 to MP 187.2, past Forbes, very curvily south (including a pair of horseshoe curves), past Toecane, Roses Branch, Bandana and Lunday, south-southeast, past the 6,992 ft. east-side siding (20 mph on the siding), from North Kona (MP 172.1) to South Kona (MP 173.5), where an erstwhile shortline to Eskota once left on the west side, and curvily east, past Boonford, Wing, where an erstwhile branch once headed south, a detector at Penland (MP 179.6), and Minpro, where it turns curvily southeast.
There is a north-facing signal at Spruce Pine Holdout (MP 182.0), Spruce Pine Yard, on the east side, from MP 182.6 to MP 183.6, with a crossover at MP 183.1, a dual-ended spur on the east side for US Gypsum, from MP 184.1 to MP 184.5, the 7,090 ft. west-side siding (20 mph on the siding) from North Toe River (MP 185.3) to South Toe River (MP 186.5), a short tunnel and the summit at Altapass, descending through "The Loops", with a 30 mph speed restriction from MP 187.2 to MP 203.6, south-southwest past a tunnel, Switzerland, and four more tunnels, making a counter-clockwise horseshoe back to the north-northeast, just below the earlier line, past six more tunnels, then making a clockwise horseshoe around to the south, past two more tunnels, a coiunter-clockwise horseshoe to the northeast, past the 8,154 ft. east-side siding (30 mph on the siding), from North Rocky (MP 195.9) to South Rocky (MP 197.6), a clockwise horseshoe to the southwest, a sharp turn just north of due east, past another tunnel and Ash Ford, and a clockwise horseshoe to the southwest, past MP 203.6, where the full line speed of 45 mph prevails and a detector at Avery (MP 205.1).
The line turns west, past North Cove, southwest, past Pitt, curvily south, past a 40 mph speed restriction, from MP 209.8 [sic] to MP 212.8, the 6,628 ft. west-side siding, from North Sevier (MP 208.9) to South Sevier (MP 210.2), a 35 mph speed restriction, from MP 212.8 to MP 219.8, and Hankins, southeast, past the 6,407 ft. east-side siding, from North Marion (MP 217.7) to South Marion (MP 219.0), passing beneath the former Southern Salisbury to Asheville line, with a southeast quadrant connector at Clinchcross, turning just west of due south, through a tunnel, southeast, south-southwest, past MP 219.8, where the 45 mph full line speed prevails, and a detector at "Glenwood" (MP 225.2), curvily south, with a 40 mph speed restriction, from MP 227.9 to MP 230.3, past Fero, with the routing of an erstwhile Southern line nearby to the west, a 35 mph speed restriction, from MP 230.3 to MP 230.6, and a 40 mph speed restriction, from MP 230.6 to MP 231.5, where the maximum speed becomes 50 mph and prevails.
There is a 6,672 ft. west-side siding, from North Thermal (MP 232.3) to South Thermal (MP 233.6), where the line turns southeast, Tate, a detector at "Keefe" (MP 238.2), and Logan, a 40 mph speed restriction, from MP 241.6 to MP 245.4, and the 6,808 ft. east-side siding from North Bostic (MP 243.3), where the Back Lead (10 mph) goes off on the east side (MP 243.6), past Bostic Yard on the east side, to South Bostic (MP 245.0), where the Charlotte subdivision from Florence trails in on the east side and the line turns south.