Crooked Run begins on Catawissa Mountain in North Union Township. It flows east-southeast for a few tenths of a mile before turning roughly east for some distance and eventually flowing off Catawissa Mountain. The stream then turns northeast and begins to skirt the edge of the mountain for more than a mile. It then turns north for a few tenths of a mile, crossing Raricks Road, before turning west and then north again, flowing parallel to Bunker Hill Road for a few tenths of a mile. Several tenths of a mile downstream, the stream reaches its confluence with Catawissa Creek, a few hundred feet from the border between Schuylkill County and Columbia County.
