was a district located in Niigata Prefecture, Japan. History On 1954 - areas now covering Ojiya were merged and elevated to city status. On November 1, 2004 - towns of Horinouchi and Koide, and the villages of Hirokami, Irihirose, Sumon and Yunotani were merged to create the city of Uonuma; leaving the village of Kawaguchi the only municipality within the district. On March 31, 2010 - the town of Kawaguchi was merged into the expanded city of Nagaoka. Kitauonuma District was dissolved as the result of this merger. Former districts of Niigata Prefecture