The is a railway line in Japan. Part of the East Japan Railway Company (JR East) system, it runs from Sendai Station in Sendai, Miyagi Prefecture to Uzen-Chitose Station in Yamagata, Yamagata Prefecture, acting as a connector between the Tōhoku Main Line/Tōhoku Shinkansen and the Ōu Main Line in southern Tōhoku. It also provides access to western Miyagi Prefecture and eastern Yamagata Prefecture. It connects with the Tōhoku Shinkansen, Tōhoku Main Line and Senseki Line at Sendai Station, the Ōu Main Line at Uzen-Chitose, Kita-Yamagata, and Yamagata Stations in Yamagata, Yamagata, the Aterazawa Line at Kita-Yamagata and Yamagata Stations, and the Yamagata Shinkansen at Yamagata Station. History September 29, 1929: Senzan East Line begins operation (Sendai — Ayashi). Kita-Sendai, Rikuzen-Ochiai, and Ayashi Stations open. August 30, 1931: Ayashi — Sakunami connection opens. Rikuzen-Shirasawa, Kumagane, and Sakunami Stations open. October 17, 1933: Senzan West Line begins operation (Uzen-Chitose — Yamadera). Yamadera Station opens. November 10, 1937: Sakunami — Yamadera connection opens. Senzan Line connects Sendai and Uzen-Chitose Stations. Sakunami — Yamadera tracks are electrified (1,500 V DC). Oku-Nikkawa Station opens. Omoshiroyama signal box begins operation. Temporary stations Yatsumori and Omoshiroyama open. July 1, 1950: Takase Station opens. August 10, 1955: Rikuzen-Ochiai — Kumagane tracks are electrified (20 kV 50 Hz AC). September 5, 1957: Sendai — Rikuzen-Ochiai, Kumagane — Sakunami tracks are electrified (20 kV 50 Hz AC). ED45 (ED91) electric locomotive enters service. November 1, 1960: Yamadera — Uzen-Chitose (— Yamagata) is electrified (1,500 V DC). "Asahi" and "Gassan" semi-expresses begin operation. October 1, 1963: "Senzan" semi-express begins operation. March 5, 1966: "Asahi" and "Gassan" become expresses. September 8, 1968: Sakunami — Uzen-Chitose (— Yamagata) switched to 20 kV 50 Hz AC electrification. ED78 electric locomotive begins operation October 1, 1968: "Senzan" semi-express becomes an express. 1971: Kumagane Station becomes unmanned. October 2, 1978: "Senzan" express begins making stops at Ayashi station. May 1, 1982: "Asahi" express becomes "Benibana". November 15, 1982: "Senzan" express becomes a rapid train. "Gassan" ceases operations within the Senzan Line. February 1, 1984: Kitayama and Kunimi Stations open. Third platform built at Ayashi Station. March 14, 1985: Senzan Line utilizes CTC. Rikuzen-Ochiai, Rikuzen-Shirasawa, Sakunami, Oku-Nikkawa, and Tateyama Stations become unmanned. March 1, 1987: Some staff from Sendai Station are transferred to Kitayama and Rikuzen-Ochiai Stations. March 20, 1987: Some staff from Sendai Station are transferred to Kunimi Station. March 21, 1987: Nishi-Sendai Hi-Land Station opens