Marion County SR 27 begins as it
runs concurrently as a
secret, or hidden, designation, with
U.S. Route 72 (US 72) once that highway enters Tennessee from
Jackson County, Alabama. This point also marks the eastern terminus of unsigned
Alabama State Route 2. During SR 27's concurrency with US 72 in Marion County, it traverses the cities of South Pittsburg,
Kimball, and the Marion County seat of
Jasper, as well as the exit 152 interchange on
Interstate 24, where they pick up
US 64. They then pick up
SR 2 so it, too becomes a secret designation. They join
US 41 in Jasper. SR 27 departs from US 41/US 64/US 72 and SR 2 near
Nickajack Lake, and then SR 27 travels northward to
Powells Crossroads. After the brief concurrency with
SR 283 in that area, SR 27 changes from a secondary route to a primary one, and then enters Hamilton County.
Hamilton County Near
Signal Mountain, SR 27 once again becomes a hidden route when it joins
US 127 as well as another secret designation in
SR 8 just within Chattanooga's northern outskirts. SR 27 then joins
US 27 (SR 29), still as a secret designation for the rest of its course southeastward, including the segment of the US 27 freeway that also has an unsigned designation of
Interstate 124 (I-124). US 27 and SR 27 passes through downtown Chattanooga, with a brief concurrency with
I-24 between exits 178 and 180, and then it turns southward, still following US 27, and for SR 27 to terminate at the Georgia state line, which in this area, it coincides with the Chattanooga city limits, as well as those of
Rossville, Georgia and
Walker County's northern boundary. US 27 continues southward with
Georgia State Route 1 into the northwest Georgia counties of Walker and
Catoosa. ==Major intersections==