[CSteefel]

Interesting question. I always assumed that the High Pass was much farther north than they wanted to go, especially since they wanted to pass through Lorien (either Caradhras or Moria would get them this). But also, it seems that whatever the searches turned up, the raiding party of Orcs that freed Gollum may have influenced the thinking as well, since it was clear that the Enemy was moving almost at will in this general region. Perhaps a route down on the west side of the river, however, would have given better results...