Answers:

10: Topsfield, ME; Bridgewater, ME; Marquand, MO; and Marblehead, OH. At the first three sites, the radar tower doubled as a fire-lookout tower. However, the Marquand site reportedly never became an operational radar facility, although apparently the tower itself was constructed. At the Marblehead site, it is unclear just why a 4-legged tower was used, as it did not have a fire-lookout function. If anyone knows for sure, please contact us and let us know thanks. Also, if anyone knows of any other 4-legged gap-filler radar towers, please contact us and let us know that, too thanks again.