Huntingdon and Franklin counties

PA 641 eastbound in Dublin Township

PA 641 begins at an intersection with US 522 north of the borough of Shade Gap in Dublin Township, Huntingdon County, heading east on two-lane undivided road past homes and businesses and soon crossing PA 35. Past here, the road curves to the southeast and runs past more development before heading into forested areas. The route continues through woodland with sparse homes and curves to the east, running through a mix of fields and trees and passing through the community of Neelyton. PA 641 heads back into forests and turns northeast to ascend Tuscarora Mountain. The road makes a hairpin turn to the south and continues to climb the mountain.^[2][3]

At the summit of Tuscarora Mountain, the route enters Fannett Township in Franklin County and continues south as it begins to descend the mountain, making a hairpin turn to the northeast and becoming Spring Run Road. PA 641 makes another hairpin turn to the southwest before curving southeast to reach the base of the mountain. The road heads into farmland with some woods and homes, coming to an intersection with PA 75 in the community of Spring Run. From here, the route winds south through more farms and woods before passing to the west of a forested mountain.^[2][4]

PA 641 turns east and curves southeast to pass under the Pennsylvania Turnpike (I-76). Immediately after, the route turns south onto Timmons Road, with PA 641 Truck continuing east as Amberson Road. PA 641 continues through farmland with some woods before it curves east into forested areas, where it heads northeast to ascend Kittatinny Mountain. At the summit, the road makes a hairpin turn to the southeast to descend the mountain. The route curves northeast and then south to intersect the eastern terminus of PA 641 Truck at the base of the mountain.^[2][4]

PA 641 continues east into Lurgan Township and becomes Forge Hill Road, winding east through forests and traversing Blue Mountain. Past the mountain, the road heads east into the community of Roxbury, where it passes homes and a few businesses and comes to an intersection with PA 997. At this point, PA 997 turns east for a concurrency with PA 641 before it splits to the north. PA 641 continues east and leaves Roxbury, where it becomes Newburg Road and heads east-northeast through farmland with some trees and residences, passing through the community of Otterbein.^[2][4]

Cumberland County

PA 641 westbound in Newburg

After crossing Laughlin Run, this route enters Hopewell Township in Cumberland County and continues through agricultural areas with a few homes. PA 641 enters the borough of Newburg and becomes West Main Street, passing homes and forming a one-block concurrency with PA 696. The road crosses High Street and becomes East Main Street, running past more residences before leaving Newburg for Hopewell Township again. Here, the route becomes Newville Road and runs east-northeast through farmland with scattered homes.^[2][5]

PA 641 heads east into a mix of fields and woods and crosses Conodoguinet Creek, curving northeast and heading into North Newton Township. The road becomes Greenspring Road and runs east through a mix of farms, woods, and homes. The route reaches the community of Green Spring and turns northeast, running through more rural areas with some development.^[2][5]

PA 641 becomes the border between North Newton Township to the north and the borough of Newville to the south before it fully enters Newville and becomes Main Street, passing homes. In the center of Newville, the route crosses PA 233 and continues through more of the borough. The road crosses Big Spring Creek and leaves Newville for West Pennsboro Township, where the name becomes Carlisle Road and it passes residences and a few businesses.^[2][5]

PA 641 continues northeast through farmland with some woods and homes, passing through Bears Crossroads and West Hill, where the name changes to Newville Road. At this point, the route runs a short distance to the south of the Pennsylvania Turnpike (I-76) and runs through a mix of farmland and residences before it heads through the community of Plainfield, where it becomes Main Street and passes homes and a few businesses. From here, the road becomes Newville Road again and heads through agricultural areas with some development, passing to the north of the community of Elliottson.^[2][5]

PA 641 enters North Middleton Township and passes between warehouses to the north and homes and fields to the south as it comes to an intersection with the northern terminus of PA 465. The road continues through a mix of residential and commercial development as it crosses into the borough of Carlisle. Here, PA 641 turns south onto North Orange Street and passes under Norfolk Southern's Shippensburg Secondary railroad line before it comes to an intersection with US 11.^[2][5]

At this point, PA 641 turns east for a concurrency with US 11 on West High Street, passing between the railroad tracks to the north and businesses to the south. The railroad tracks head further to the north and the road continues east through the campus of Dickinson College, passing to the north of a few homes and businesses. US 11/PA 641 runs through more of the college campus and comes to an intersection with PA 74, at which point that route joins US 11/PA 641 on West High Street. The three routes head into the commercial downtown of Carlisle, where it comes to an intersection with PA 34 at Hanover Street at the center of town.^[2][5]

Here, US 11 turns north to follow PA 34 while PA 74/PA 641 continue east on East High Street, heading through more of the downtown. Past the downtown area, the road runs past homes before passing businesses as a three-lane road with a center left-turn lane. PA 74 splits from PA 641 by heading southeast on York Road, providing access to southbound I-81. PA 641 continues east along East High Street and passes north of The Point at Carlisle Plaza shopping mall, leaving Carlisle and becoming the border between North Middleton Township to the north and South Middleton Township to the south and heading into residential areas on two-lane West Trindle Road.^[2][5]

The route becomes the border between Middlesex Township to the north and South Middleton Township to the south and widens into a four-lane divided highway and reaches a partial interchange with I-81, providing access to the northbound lanes and from the southbound lanes of I-81.^[2][5]

PA 641 westbound past eastern terminus at US 11/US 15 in Camp Hill

Past the I-81 interchange, the route passes businesses and narrows back to a two-lane undivided road. The road heads through farmland before heading through a mix of woods and homes and passing through the community of Hickorytown.^[2][5]

PA 641 continues through a mix of farms, woods, and residences, becoming the border between Silver Spring Township to the north and Monroe Township to the south, crossing the Appalachian Trail at Stony Ridge. Farther east, the roadway passes through the community of Locust Point. The route bends to the east-northeast and comes to an intersection with the eastern terminus of PA 174 in the community of Roxbury. The road comes to a bridge over the Pennsylvania Turnpike (I-76) and heads into residential areas, passing through the community of Trindle Spring. PA 641 enters the borough of Mechanicsburg and becomes West Main Street, passing a mix of homes and businesses. The route comes to an intersection with PA 114, which heads north (west), where that route forms a concurrency with PA 641. The two routes head into the commercial downtown of Mechanicsburg, where PA 114 splits to the south (east). PA 641 continues along East Main Street and runs through residential areas. The route heads into business areas and leaves Mechanicsburg for Hampden Township, where it becomes East Trindle Road and crosses Norfolk Southern's Shippensburg Secondary at-grade. The road continues northeast past homes and commercial establishments a short distance to the south of Naval Support Activity Mechanicsburg.^[2][5]

PA 641 passes under a Norfolk Southern branch line serving the naval facility and continues through developed areas. The route comes to a partial interchange with the US 11/PA 581 freeway (Capital Beltway), with access to northbound US 11/eastbound PA 581 and from southbound US 11/westbound PA 581. Past this interchange, the road continues through residential and commercial areas, entering the borough of Camp Hill. Here, PA 641 becomes a three-lane road with a center left-turn lane and passes north of the Camp Hill Shopping Center before it comes to its eastern terminus at an intersection with US 11/US 15. Past this intersection, the road continues east as Chestnut Street, a local street.^[2][5]