Etymology and distribution of 下広.

Shimohiro 【下広】^{レベル3
About 200}  The Japanese surnames etymology dictionary.

Ibaraki-ken , Saitama-ken , Nagano-ken . A variant of 染谷 Valley. In Ibaraki-ken Toride-shi Ibaraki-ken Bandou-shi In Yumida Castle of Yumida tells that it is the descendant of Mr. Shikiya who was a castle owner during the Warring States Period. In the estimation the old pronunciation is Somaya. Saitama-ken Chichibu-gun Nagatoro-machi It was in the Edo period in Nogami Shimo . 染谷 Someya reference.