PR 588 has changed significantly from its original route. A southern leg of this route used to extend from PR 275, four miles west of the junction with the still-existing northern leg, to
PTH 83 near
Benito. Furthermore, PR 588 used to go around Lambert's hill because it was so steep, but the grade has since been cut down. Also, it used to extend further to reach PR 279 which has also changed its alignment. Overall, the original length was 46 kilometres. Part of the southern leg is now signed as
PR 487. The other part is maintained by the
Municipality of Swan Valley West. Some old provincial roadsigns still remain along this part of the route. ==Major intersections==