A.k.a. Old Lancaster road, The Lancaster road, Conestogoe road; predates European settlement as a ridge-hugging native Lenape pathway between the Delaware and Susquehanna rivers.
Victoria Donohoe:
The oldest road in Narberth is a stretch of Montgomery Avenue between N. Wynnewood Avenue and Merion Friends Meeting. It was one of the most important Indian trade routes on the East Coast during the early 17th-century Dutch and Swedish Colonial period, being the major beaver-trade path for Lancaster County Indians carrying pelts to Fort Nassau on the New Jersey side of the Delaware River at Big Timber Creek in Gloucester County.
Later called both the Conestogoe Road and the Radnor and Merion Road by the Welsh Quakers, that same section of Montgomery Avenue was in use by those settlers by 1693, according to a March 1713 Quarter Sessions road docket in the city archives.
For a long time, Montgomery Avenue did not exist east of Merion Meeting. Not before a March 1723 Quarter Sessions road docket do we find "it being an absolute nescessity" for a road to be established to connect Philadelphia's Market Street with the Haverford and Merion Road at Montgomery Avenue.