2005: Kumaishi Town (Nishi District) was merged with Yakumo Town (Yamakoshi District, Oshima Subprefecture) and transferred to Oshima Subprefecture. At the same time, Hiyama Subprefecture was divided between north and south.
2014: Esashi Line (from Kikonai Station to Esashi Station) was abolished. Therefore, Hiyama Subprefecture became the only subprefecture in which there is no railway.
External links
Wikivoyage has a travel guide for Hiyama Subprefecture.
