Hastings' Dictionary of the Bible -
Atroth-shophan
ATROTH-SHOPHAN . A town E. of Jordan, near Aroer and Jazer, fortified by Gad ( Numbers 32:35 ). Some place it with Atareth 1. at ‘Attârûs . This is hardly possible. The site is unknown.
W. Ewing.
Holman Bible Dictionary -
Atroth-shophan
(at' rahth-sshoh' fan) Town built by tribe of Gad of unknown location (Numbers 32:35 ). Earliest translations spelled name various ways: Shophar, Shaphim, Shopham, Etroth Shophan.