Not every place that had a post office was an actual town. My own family ran the Presto, Idaho, post office for 14 years from their isolated home along the Blackfoot River. It seems that the Comet Post Office had a similar, shorter history.
A reader asked if I knew anything about the town of Comet. I didn’t, partly because it wasn’t really a town. Partly because I’d never heard of the place. I found that there was a post office at Comet so that made researching it much easier. I just asked Bob.
Bob Omberg is the acknowledged expert on Idaho post offices. An attorney by trade, Bob no longer lives in Idaho, but he retains a fascination with post offices, postal marks, route maps, and such. He supplied me with some information about Comet, including a copied page from "Sagebrush Post Offices: A History of the Owyhee Country" by Mildretta Adams (copyright 1986; third printing 2003 by the Owyhee Publishing CO., Homedale Idaho).
From that book, I learned that John McVann, a local rancher, established the Comet Post Office on February 7, 1910, in Owyhee County. It was near present-day Bruneau, on the south side of the Snake River across from where Canyon Creek enters. The post office operated until January 31, 1913.
Comet is listed as one of the “drowned towns” in The Atlas of Drowned Towns, BSU Professor Bob Reinhart’s project that helps identify the many places that once existed on dry land but are now under reservoir waters.
So, was Comet a town? Probably not, but the post office site is now under the C.J. Strike Reservoir, so it does qualify as drowned.