 When originally designated in 1933, the western terminus of SR 3 was located in downtown Portland.It was overlaid on sections of SR 26, SR 4 and SR 11 between Portland and Augusta.In 1946-7, the western portion of the route was truncated to Augusta and its western terminus was moved to the intersection of Bangor Street and North Belfast Avenue, where it began cosigned with US 202 / SR 9.