From the account in The Lord of the Rings, it would be natural to assume that the North Stair ran down beside Rauros on the western side. It seems to have been part of Aragorn's original plan to use the Stair to descend into the lowlands, so the fact that he landed on the western shore, and that other Gondorian works were to be found there, would seem to imply that the North Stair was reached from the western side of the Falls.
To confuse matters slightly, however, Tolkien gives a definition for the North Stair in his extended index to The Lord of the Rings, and there he describes it as leading from the hills of Emyn Muil down into the Nindalf. Following the maps accompanying the book, the Nindalf lay on the eastern banks of Anduin, not the western. On the face of it, this seems rather odd - it hardly seems plausible that Aragorn meant to cross to the eastern bank, which was held by the enemy, to reach the bottom of the Falls. Alternatively, perhaps the Nindalf was rather wider than it appears on the canonical map, and included a region west of Rauros as well as spreading far to the east.
|