 When Pennsylvania first legislated its highways in 1911 , what would become PA 261 was legislated as part of Legislative Route 180 between the Delaware border and Chelsea . PA 261 was first designated in 1928 to run from the Delaware border to PA 61 ( Concord Road ) and PA 161 ( Chelsea Road ) in Chelsea , following Foulk Road . By 1940 , PA 261 was extended north along Valley Brook Road from US 322 ( which replaced PA 61 ) to US 1 in Chester Heights . By 1980 , the northern terminus of PA 261 was truncated to its current location at the interchange with US 322 . 
