This episode is indeed a strange choice for Rawhide's debut, and I doubt that it was the pilot for the series. Perhaps some production issue forced the producers to make this the first episode, or maybe they felt its expansive guest cast (including perky Terry Moore) would garner a wider audience. In any case, the story isn't to my liking -- it's a bit creepy, has nothing to do with the cattle drive, and has a pat ending that made me wince.
Review of Incident of the Tumbleweed
