 When Pennsylvania legislated routes in 1911, what is now PA 25 was not given a number.At this time, the highway existed as an unpaved road between Millersburg and Sacramento.PA 25 was designated in 1928 to run from US 209 in Millersburg east to PA 443 in Pine Grove, following its current alignment to Hegins before it turned southeast to Tremont and south to Pine Grove.