It runs from north to south for 160.1 miles (257.7 km), serving the counties of Forrest, Pearl River, Lamar, Marion, Jefferson Davis, Simpson, Rankin, Smith, Scott, and Leake.

MS 13 continues traveling westward through rural areas, where it passes through Young and has an interchange with I-59 (Exit 41), before crossing into Lamar County and immediately entering Lumberton.

They head west as a four-lane divided highway through a business district to have an intersection with MS 198 before crossing the Pearl River to leave Columbia and enter neighboring Foxworth.

MS 13 heads north to have an interchange with US 84's new bypass of Prentiss before leaving the town and traveling northward through an even mix of rural farmland and wooded areas for several miles to cross into Simpson County.

MS 13 heads north through wooded areas (part of the Bienville National Forest) for several miles, where it passes through Kracker Station, before having an interchange with I-20 (Exit 77) and entering Morton.

It originally entered the city from the south as Lumberton Road before becoming concurrent with MS 198/MS 35 (S High School Avenue; then part of US 98).

They headed north along High School Avenue past some businesses and neighborhoods before coming to an intersection with Broad Street.