is a subprefecture of Hokkaido Prefecture, Japan corresponding to the old province of Tokachi. As of 2004, its estimated population is 360,802 and its area is 10,830.99 km2. Tokachi-Obihiro Airport is in the city of Obihiro. Geography Municipalities Mergers History November 1897: Kasai Subprefecture established. August 1932: Kasai Subprefecture renamed Tokachi Subprefecture. October 20, 1948: Ashoro District transferred from Kushiro Subprefecture. References External links Official website Subprefectures in Hokkaido