A climbing steps rail set includes a first molded plastic rail having a lower end configured to rest on a lower support surface, an upper end configured to be coupled to an elevated support structure, and a first plurality of apertures formed in the rail and configured to receive respective first ends of steps to be supported by the rail set. The rail set further includes a second molded plastic rail having a lower end configured to rest on the lower support surface, an upper end configured to be coupled to the elevated support structure, and a second plurality of apertures formed in the rail and configured to receive respective second ends of the steps to be supported by the rail set.