York County PA 74 begins at the
Maryland border in
Peach Bottom Township in
York County, where the road continues south into that state as
MD 165. From the state line, the route heads north as two-lane undivided Delta Road, passing through fields and woods with commercial development as it bypasses the borough of
Delta to the west. The road curves northeast and then north and intersects the eastern terminus of
PA 851 and Broad Street at a
roundabout. PA 74 continues north through a mix of farmland and woodland with some homes, curving to the northwest and crossing the
Muddy Creek into
Lower Chanceford Township. The route turns west to remain along Delta Road and curves northwest through more agricultural areas with occasional residences. The road intersects the western terminus of
PA 372 before it passes through the communities of
Sunnyburn and Kyleville. Farther northwest, PA 74 reaches the community of
Airville, where it intersects
PA 425 and forms a
concurrency with that route. The two routes curve west and pass residences and businesses before PA 425 splits to the southwest. PA 74 continues northwest through farmland with some wooded areas and homes. The route enters
Chanceford Township and passes through the community of Collinsville, where it heads near homes before running past farms and a few businesses. The road curves to the west and heads through the community of
Brogue as it runs through agricultural areas with some development. PA 74 runs west-northwest through more rural land and passes through the community of
Keys before it crosses into
Windsor Township. Here, residential development along the route increases as it continues near more farms with some woods, passing through the community of Petersburg and curving to the west. PA 74 forms the border between Windsor Township to the north and the borough of
Red Lion to the south before it fully enters Red Lion and becomes East Broadway, passing through residential areas. The road heads past more homes and a few businesses before it reaches the downtown area of Red Lion and comes to an intersection with
PA 24. At this intersection, the route turns southwest and becomes West Broadway, heading past residences and curving to the west. PA 74 leaves Red Lion for
York Township and gains a
center left-turn lane as it passes businesses, turning northwest and becoming East Main Street. The road narrows to two lanes and passes through residential areas as it enters the borough of
Dallastown. The route curves west and runs past homes and some businesses, reaching an intersection with the eastern terminus of
PA 214. PA 74 passes through the downtown area of Dallastown, with the name changing to West Main Street after crossing Walnut Street. The road passes more homes and turns to the northwest before it leaves Dallastown for York Township and turns to the west, becoming South Queen Street. The route passes fields to the north and residential areas to the south before it runs past businesses. PA 74 makes a turn to the north-northwest and gains a center left-turn lane, heading through more commercial areas and coming to an intersection with the eastern terminus of
PA 182. Following this intersection, the road becomes two lanes again and passes through the community of
Spry, running north through residential areas with some businesses. Farther north, the route becomes a three-lane road with a center left-turn lane as it passes more suburban development. PA 74 heads past businesses and becomes a four-lane
divided highway as it passes west of the
York County School of Technology, turning northwest and coming to a
partial cloverleaf interchange with
I-83. At this point, PA 74 heads west for a concurrency with PA 641 along East High Street, a three-lane road with a center left-turn lane that passes businesses. Farther west, the road narrows to two lanes and passes homes before heading into the commercial downtown area of Carlisle. PA 74/PA 641 reach an intersection with
US 11 and
PA 34 at Hanover Street at the center of town adjacent to the Cumberland County Courthouse, where US 11 turns west to join PA 74/PA 641 on West High Street. The three routes head west through more of the downtown area before passing through the campus of
Dickinson College. PA 74 splits from US 11/PA 641 by turning north onto North College Street, running through more of the college campus before crossing Norfolk Southern's Shippensburg Secondary railroad line and heading into residential areas. The route turns west onto B Street at a roundabout and northwest onto Waggoners Gap Road as it passes more homes. The road becomes the border between Carlisle to the southwest and
North Middleton Township to the northeast before it fully enters North Middleton Township and passes under the
Pennsylvania Turnpike (
I-76). PA 74 runs north-northwest through farmland with some homes before it curves northwest and crosses the
Conodoguinet Creek. The route runs through a mix of farm fields and residential development, heading through the community of
Caprivi. Farther northwest, the road comes to an intersection with
PA 944. PA 74 passes more farms before it enters forested areas and begins to ascend
Blue Mountain, turning northwest and then northeast. The road makes a
hairpin turn to the west and crosses into
Lower Frankford Township as it reaches the summit of the mountain. PA 74 enters
Turbett Township in
Juniata County and becomes an unnamed road, turning southwest to ascend Tuscarora Mountain. The road makes a hairpin turn to the northeast and reaches the summit of the mountain. From here, the route turns sharply to the west to begin to descend the mountain. PA 74 makes a hairpin turn to the northeast, a hairpin turn to the west, and a sharp turn to the north to reach the base of the mountain. The route heads into farmland and makes a turn to the east and a turn to the north. PA 74 heads north through agricultural areas with some woodland and reaches its northern terminus at an intersection with
PA 75. ==Major intersections==