McPherson Ridge rises in front of you, a landform central to the 1863 Battle of Gettysburg. Here the I Corps of the Union Army had a headquarters on the ridge and was defeated by the Confederate division of Major General Henry Heth. The ridge rises to terrain above roughly 530 ft (160 m), with summit areas above 560 ft (170 m) that include four on or near the Lincoln Highway, a broader summit south of the Fairfield Road, and a larger plateau at the northern saddle.
The northern end is a slight topographic saddle point on the west edge of Oak Ridge. Much of this ground is federally protected, although township portions remain at the southern end and along Pennsylvania Route 116, where a PennDOT facility sits. Long before the battle, travel shaped this ridge: in 1747 the Nichol's Gap Road — later called the Hagerstown Road and now the Fairfield Road — was cut over the height; the road to the north became the 1809 turnpike from Gettysburg to Black's Gap and was extended to Chambersburg in 1810.
In 1835 Middle Ridge held the middle of three railway cuts excavated for the Tapeworm Railroad, and by the 1850s the Old Mill Road crossed northwest from the Hagerstown Road. The ridge climbs toward that northern saddle point, where the ground settles into the west edge of Oak Ridge before your next steps.