Analysis of information sources in references of the Wikipedia article "Nagaoka, Niigata" in English language version.
Nakanoshima-machi, Koshiji-machi, Mishima-machi, Yamakoshi-mura and Oguni-machi were incorporated into Nagaoka-shi as of April 1, 2005.
Tochio-shi, Washima-mura, Teradomari-machi and Yoita-machi were incorporated into Nagaoka-shi as of January 1, 2006.
平成17年4月1日に南蒲原郡中之島町、三島郡三島町、古志郡山古志村、刈羽郡小国町と一緒に長岡市に編入合併しました。