Kisuki Line

The northern end of the route began as a private venture. The Hikami Light Railway was granted a railway licence on 31 January 1914 and, after reorganising as the Hikami Railway, opened the section between Shinji and Kisuki — a distance of 13.1 miles, about 21.08 km — on 11 October 1916. The young company at first relied on a government subsidy but traded soundly, and from 1927 it boosted its freight earnings by carrying construction materials for the state's railway being built south of Kisuki. In 1930 it converted its operating distances from miles to metric units.

The state then built southward from Kisuki under the name Kisuki Line. The first government-built segment, from Kisuki to Izumo-Minari (20.4 km), opened on 18 December 1932. On 1 August 1934 the privately owned Hikami Railway was nationalised, bringing the Shinji–Kisuki section into the state line. The route was pushed further into the mountains with the opening of Izumo-Minari to Yakawa (14.8 km) on 20 November 1934, and the final segment from Yakawa to Bingo-Ochiai (25.6 km) opened on 12 December 1937, completing the through line and joining it to the Geibi Line at Bingo-Ochiai.

Crossing the watershed of the Chūgoku Mountains demanded heavy engineering. South of Yakawa the gradient reaches 30 per mille, and the line climbs over the high ground from Izumo-Sakane Station by means of a two-stage switchback before passing through the Chūō-Sakane tunnel. It then reaches Miinohara, which at an elevation of 727 metres is the highest station on the entire JR West network, before descending into Hiroshima Prefecture; from this stretch travellers can look out on the "Okuizumo Orochi Loop," the spiralling loop bridge that carries National Route 314 through the same pass.

In the post-war decades the line saw a series of smaller additions and changes. A temporary halt at Mitsui-no-hara opened on 24 December 1949 and was upgraded to a full station, Miinohara, on 1 September 1958; Minami-Shinji Station opened on 1 January 1962 and Minami-Daitō on 1 October 1963. Steam haulage was withdrawn on 25 April 1969, and all freight operations on the line ended on 7 November 1982.

With the privatisation and break-up of Japanese National Railways on 1 April 1987, the Kisuki Line passed to JR West. Under the new operator its through services were progressively reduced: the "Chidori" express was curtailed and the line's limited-express and express trains were withdrawn on 10 March 1990, and from 24 April 1993 all services were standardised on KiHa 120 railcars.

To encourage use of the scenic but loss-making line, JR West introduced a seasonal sightseeing service. From 25 April 1998 the "Okuizumo Orochi-gō" trolley train ran on the Kisuki Line during the holiday seasons, becoming the line's best-known attraction. As its rolling stock aged the service was ended on 23 November 2023, and a successor sightseeing train, the "Ametsuchi," began running from 7 April 2024.

• 191431 January: the Hikami Light Railway is granted a railway licence for the Shinji–Kisuki area.
• 191611 October: the Hikami Railway opens the Shinji–Kisuki section (13.1 miles ≈ 21.08 km), with Kamonaka, Daitō-machi (now Izumo-Daitō) and Kisuki stations.
• 19301 April: the Hikami Railway converts its operating distance from miles to metric units (13.1 mi → 21.1 km).
• 193218 December: the state-built Kisuki Line opens between Kisuki and Izumo-Minari (20.4 km).
• 19341 August: the privately owned Hikami Railway is nationalised, bringing the Shinji–Kisuki section into the state line.
• 193420 November: the line is extended from Izumo-Minari to Yakawa (14.8 km).
• 193712 December: the final segment, Yakawa to Bingo-Ochiai (25.6 km), opens, completing the through line — including the switchback at Izumo-Sakane — and joining it to the Geibi Line.
• 194924 December: a temporary halt opens at Mitsui-no-hara.
• 19581 September: the Mitsui-no-hara halt is upgraded to Miinohara Station, at 727 m the highest station on the JR West network.
• 196925 April: steam locomotive operation on the line is discontinued (dieselisation).
• 19827 November: all freight operations on the line are abolished.
• 19871 April: on the privatisation of Japanese National Railways, the line passes to JR West.
• 199010 March: the 'Chidori' express is curtailed and the line's limited-express/express services are withdrawn.
• 199324 April: services are standardised on KiHa 120 diesel railcars.
• 199825 April: the 'Okuizumo Orochi-gō' trolley sightseeing train begins seasonal operation to promote use of the line.
• 202323 November: the ageing 'Okuizumo Orochi-gō' makes its final run.
• 20247 April: the 'Ametsuchi' sightseeing train begins running as the Orochi-gō's successor.