I-77 heads east as a six-lane freeway that crosses over CSX's Columbia Subdivision and has a diamond interchange with South Carolina Highway 35 (SC 35; 12th Street Extension).

I-77 enters the city of Columbia at its crossings of Norfolk Southern Railway's SC Line and CSX's Eastover Subdivision.

The freeway veers north and leaves the military base and the city of Columbia at its partial cloverleaf interchange with SC 12 (Percival Road).

I-77 passes through the unincorporated suburb of Woodfield and meets I-20 at an interchange with a pair of flyover ramps; there is no access from eastbound I-20 to northbound I-77.

I-77 meets SC 34 west of the town of Ridgeway and passes under Norfolk Southern Railway's R-Line.

I-77 expands to eight lanes at its partial cloverleaf interchange with US 21 and SC 5 (Anderson Road) and enters the city of Rock Hill.

The freeway has a diamond interchange with SC 122 (Dave Lyle Boulevard) west of the Rock Hill Galleria.

At the partial cloverleaf interchange, US 21 begins to run concurrently with I-77; the two highways cross the state line together into the city of Charlotte.

The South Carolina Department of Transportation (SCDOT) operates and maintains one welcome center and two rest areas along I-77.

The South Carolina Department of Public Safety (SCDPS) and State Transport Police (STP) operate and maintain two truck inspection/weigh stations.

However, one year prior, I-77's southern terminus was changed to end at I-26, in Cayce; this created the establishment of Temporary I-77 around Columbia.

The new interchange was originally intended to serve the Carolina Panthers headquarters and practice facility, which was later scrapped.

The 20-mile (32 km) routing affixed temporary shields from 1986 to 1995, when I-77 was extended south to its current southern terminus.

[7] Interstate 326 (I-326) was an unsigned designation of the six-lane limited-access highway that traversed from I-26, in Cayce, to SC 48, in Columbia.