History
The line was originally built as part of a link between mainland Japan and Karafuto (the southern half of Sakhalin Island), then a Japanese northern frontier. From Wakkanai Port a rail-connected ferry to Ōdomari (present-day Korsakov) operated until the end of World War II. Construction began under the Hokkaido Government Railway, which opened the first segment from Asahikawa to Nagayama on 12 August 1898 as the Teshio Line. The railway was extended to Nayoro on 3 September 1903, after which construction continued under the state-run Imperial Japanese Government Railways, to which the line was transferred on 1 April 1905. In 1922 the railway reached Wakkanai — present Minami-Wakkanai — along the route that later became the Tempoku Line, running via Hamatombetsu. The present alignment via Horonobe was opened separately as the Teshio Line, with the southern (Teshio South) and northern (Teshio North) sections connected on 25 September 1926.
The line's name changed several times as it was extended: the Asahikawa–Onnenai section was renamed from Teshio Line to Sōya Line in September 1912, the title Sōya Main Line first appeared in 1919, and after a series of further renamings the whole Teshio Line was incorporated into the Sōya Main Line on 1 April 1930, at which point the Hamatombetsu-route section was separated off as the Kitami Line (later the Tempoku Line). Beyond carrying traffic to the Sakhalin ferry, the railway and its many branch lines were an important freight artery, moving timber, coal and other minerals and marine products out of northern Hokkaido in place of river transport on the Teshio River, whose right bank the line follows between Shibetsu and Horonobe.
After Japan's defeat in the war the line lost its function as a link to Sakhalin when the Chihaku ferry ceased operation in August 1945, but it remained important as a trunk route into northern Hokkaido. From around 1955 many local trains were converted to diesel railcars. Over the following decades the Sōya Main Line gradually lost all of its branch lines — among them the Nayoro Main Line (closed 1989), the Shinmei Line (1995), the Haboro Line (1987), the Bikō Line (1985) and the Tempoku Line (1989) — and today it constitutes a long branch extending from the Hakodate Main Line. One of the abandoned projects connected with the line, an extension of the Bifuka branch toward Kitami Esashi, had 13.3 billion yen expended on it before being abandoned in 1979.
Operationally the line was modernised in stages during the 1980s, and in 1986 centralised traffic control was introduced over the greater part of the line, leaving most stations unstaffed. On 1 April 1987 Japanese National Railways was privatised and JR Hokkaido succeeded to the whole line as a Category 1 operator, with Japan Freight Railway as a Category 2 operator between Asahikawa and Nayoro. A high-speed upgrade of the Asahikawa–Nayoro section was completed on 11 March 2000, raising the maximum speed on that section from 95 to 130 km/h and launching the line's first regular limited express services — Super Sōya, Sarobetsu and Rishiri. The Super Sōya was later slowed, and from 15 March 2014 the maximum speed between Asahikawa and Nayoro was reduced to 120 km/h. In a 4 March 2017 timetable revision the limited express network was reorganised into one Sōya round trip between Sapporo and Wakkanai and two Sarobetsu round trips between Asahikawa and Wakkanai, all worked by KiHa 261 series trains.
Today JR Hokkaido runs one Sōya limited express each way daily between Sapporo and Wakkanai and two Sarobetsu limited expresses each way between Asahikawa and Wakkanai, supplemented by all-stations local trains (roughly every 1–2 hours between Asahikawa and Nayoro, and every 3–4 hours between Nayoro and Wakkanai) and four Rapid Nayoro services each way daily. The current maximum speed is 120 km/h between Asahikawa and Nayoro and 95 km/h between Nayoro and Wakkanai. The line's future has come into question: on 18 November 2016 JR Hokkaido announced plans to rationalise the network by as much as 1,237 km — about half of the company's railways — and the Nayoro–Wakkanai section was among the sections it said it could not maintain on its own. For that section the company's announcement proposed talks with local communities on cost cuts, fare increases, measures to encourage use and separating ownership of the infrastructure from train operation, after which it would consider whether to keep the service as a railway.
In February 1909 a carriage nearly ran away on the Shiokari Pass in an accident that killed a railway employee; the incident became the subject of Ayako Miura's novel Shiokari Pass.
Stations on this line
38 stations tracked on the map, listed alphabetically. Select any to read its page.
- Asahikawa旭川
- Asahikawa-yojo旭川四条
- Bakkai抜海
- Bifuka美深
- Chiebun智恵文
- Chihoku智北
- Furen風連
- Horonobe幌延
- Kabutonuma兜沼
- Kembuchi剣淵
- Kita-Nagayama北永山
- Minami-Horonobe南幌延
- Minami-Wakkanai南稚内
- Mizuho瑞穂
- Nagayama (Hokkaido)永山
- Nayoro名寄
- Nayorokoko名寄高校
- Nisshin (Hokkaido)日進
- Nukanan糠南
- Onoppunai雄信内
- Osashima筬島
- Otoineppu音威子府
- Pippu比布
- Ranru蘭留
- Sakkuru咲来
- Saku佐久
- Shibetsu士別
- Shimonuma下沼
- Shin-Asahikawa新旭川
- Shiokari塩狩
- Tayoro多寄
- Teshiogawa-Onsen天塩川温泉
- Teshionakagawa天塩中川
- Toikanbetsu問寒別
- Toyotomi豊富
- Wakkanai稚内
- Wassamu和寒
- Yuchi勇知
Timeline
- 189812 August: opens as the Teshio Line of the Hokkaido Government Railway between Asahikawa and Nagayama.
- 19033 September: extended to Nayoro.
- 19051 April: transferred to the (Imperial) Japanese Government Railways.
- 190928 February: a carriage nearly runs away on the Shiokari Pass in an accident that kills a railway employee; later the subject of Ayako Miura's novel Shiokari Pass.
- 191221 September: Asahikawa–Onnenai section renamed from Teshio Line to Sōya Line.
- 191920 October: the name Sōya Main Line is used for the first time.
- 19221 November: completed to Wakkanai (present Minami-Wakkanai) via the route that later became the Tempoku Line, through Hamatombetsu.
- 192625 September: the Teshio South and North lines (the present route via Horonobe) are connected, completing that alignment.
- 19301 April: the entire Teshio Line is incorporated into the Sōya Main Line; the Hamatombetsu-route section is separated as the Kitami Line (later the Tempoku Line).
- 194525 August: the Chihaku (Wakkanai–Ōdomari) ferry ceases operation when all of Sakhalin passes to the Soviet Union.
- 196515 July: the Shimodaira Tunnel and a realignment open to avoid an avalanche trouble-spot.
- 19871 April: JNR is privatised; JR Hokkaido takes the whole line as a Category 1 operator and JR Freight operates Asahikawa–Nayoro as a Category 2 operator.
- 200011 March: the Asahikawa–Nayoro upgrade is completed, raising the maximum speed there from 95 to 130 km/h; the Super Sōya (with Sarobetsu and Rishiri) limited expresses begin.
- 201415 March: with the Super Sōya slowed, the maximum speed between Asahikawa and Nayoro is reduced to 120 km/h.
- 201618 November: JR Hokkaido announces plans to rationalise up to 1,237 km (~50% of the network); the Nayoro–Wakkanai section is among the sections it says it cannot maintain on its own, and the company proposes talks with local communities on how the railway might be kept.
- 20174 March: limited expresses reorganised into one Sōya round trip (Sapporo–Wakkanai) and two Sarobetsu round trips (Asahikawa–Wakkanai), all using KiHa 261 series.
Sources
Last updated 16 October 2026.
Gallery 4 photos
Every photo for this page. Tap any image to view it full-size. All from Wikimedia Commons (credit under each).