Why are there sycamore trees lining Route 147 near Halifax?

HALIFAX, Pa. (WHTM) -- If you've driven between Millersburg and Harrisburg "around the mountain," you've probably noticed lines of sycamore trees alongside Route 147. The scene on either side of Halifax is reminiscent of some city boulevards, like Hamilton Street in Allentown. In either case, there's a reason they're there. The tree-lined route near Halifax [...]