 In 1946, PA 37 was removed from the PA 590 alignment.While PA 37 occupied the segment of modern PA 434 from US 6 to Greeley, a spur of PA 37, Pennsylvania Route 137, occupied the remainder of PA 434 from Greeley to the state line from 1928 to 1946.In 1946, however, PA 37 was realigned to follow the entire alignment of PA 434 from US 6 to New York, decommissioning PA 137 in the process.