Kita-Shinano Line

The railway through this corridor is far older than the present line name. It opened on 1 May 1888 as a government railway between Taguchi Station (now Myōkō-Kōgen) and Nagano, continuing southward from Sekiyama; Taguchi, Kashiwabara, Mure, Toyono and Nagano stations all opened that day. When a nationwide line-naming scheme was introduced on 12 October 1909, the whole Takasaki–Niigata route was designated the Shin'etsu Line, and on 1 June 1914 it was renamed the Shin'etsu Main Line, the name the corridor would carry for over a century.

Through the first half of the twentieth century the route was steadily built up. Furuma signal station opened on 1 October 1913, was reclassified as a signal place in 1922, and became a full station on 23 December 1928; Sansai Station opened on 8 January 1958. The line and its surroundings were modernised after the Second World War: the Nagano–Naoetsu section, which includes this corridor, was electrified on 24 August 1966.

Several stations were renamed and the line was partly double-tracked in the postwar decades. Kashiwabara Station became Kurohime on 1 October 1968, and Taguchi Station became Myōkō-Kōgen on 1 October 1969. Double-tracking was carried out in two stretches — Nagano–Kita-Nagano on 28 September 1973 and Kurohime–Myōkō-Kōgen on 17 September 1980 — leaving the central part of the line single-track, as it remains. When Japanese National Railways was divided and privatised on 1 April 1987, the corridor passed to the East Japan Railway Company (JR East), with Japan Freight Railway (JR Freight) also taking it on for freight operations.

The transfer to Shinano Railway grew out of the Hokuriku Shinkansen. In 1998 it was decided that the Nagano–Naoetsu section of the Shin'etsu Main Line would be separated from JR East when the Shinkansen opened, and the governor of Nagano Prefecture agreed to the separation of the prefecture's portion on 14 January 1998. Because JR East declined to hand over the Shinonoi–Nagano stretch of the Shinonoi Line in between, the Nagano-Prefecture section would be physically cut off from Shinano Railway's existing line, so a separate line name was needed. After a council of the prefecture and lineside municipalities was set up in 2006 and Shinano Railway resolved in April 2012 to take over the Nagano–Myōkō-Kōgen section, the company's board chose the name "Kita-Shinano Line" on 27 March 2013.

The line opened under its present name on 14 March 2015, the day the Hokuriku Shinkansen extension from Nagano to Kanazawa entered service. The Niigata-Prefecture remainder of the separated corridor, from Myōkō-Kōgen north to Naoetsu, passed instead to the third-sector Echigo Tokimeki Railway as the Myōkō Haneuma Line, with a cross-platform transfer between the two companies at Myōkō-Kōgen. Services on the Kita-Shinano Line are all-stations "Local" driver-only trains, some of which continue south of Nagano onto Shinano Railway's other line, the Shinano Railway Line; JR East Iiyama Line through services also use the Nagano–Toyono section.

Since the transfer the line has continued to adjust to its operating environment. A far-reaching timetable revision on 18 March 2023 cut the number of services and lowered the maximum speed to 85 km/h, with a corresponding downgrade of the track classification, in part a response to the effects of the COVID-19 pandemic. On 14 March 2026 the Suica IC card was introduced across the whole line. The line's kilometre posts still carry their Shin'etsu Main Line values measured from Takasaki, a visible trace of the corridor's long history as part of a JNR trunk line.

• 18881 May: a government railway opens between Taguchi (now Myōkō-Kōgen) and Nagano — continuing south from Sekiyama — with Taguchi, Kashiwabara, Mure, Toyono and Nagano stations opening that day.
• 190912 October: a national line-naming scheme designates the whole Takasaki–Niigata route the Shin'etsu Line.
• 19141 June: the route is renamed the Shin'etsu Main Line.
• 192823 December: Furuma signal place (opened as a signal station on 1 October 1913) becomes a full station.
• 19588 January: Sansai Station opens.
• 196624 August: the Nagano–Naoetsu section, which includes this corridor, is electrified.
• 19681 October: Kashiwabara Station is renamed Kurohime.
• 19691 October: Taguchi Station is renamed Myōkō-Kōgen.
• 197328 September: the Nagano–Kita-Nagano section is double-tracked.
• 198017 September: the Kurohime–Myōkō-Kōgen section is double-tracked, leaving the central part of the line single-track.
• 19871 April: with the privatisation of Japanese National Railways, the corridor passes to JR East; JR Freight also takes it on for freight.
• 199814 January: the governor of Nagano Prefecture agrees that the prefecture's portion of the Nagano–Naoetsu section will be separated from JR East when the Hokuriku Shinkansen opens.
• 201217 April: Shinano Railway resolves at an extraordinary shareholders' meeting to take over the Nagano–Myōkō-Kōgen section.
• 201327 March: Shinano Railway's board decides on the line name "Kita-Shinano Line".
• 201514 March: the Kita-Shinano Line (Nagano–Myōkō-Kōgen) opens as the Hokuriku Shinkansen is extended from Nagano to Kanazawa; the Niigata-Prefecture remainder becomes the Echigo Tokimeki Railway Myōkō Haneuma Line.
• 202318 March: a far-reaching timetable revision cuts services and lowers the maximum speed to 85 km/h, with a corresponding track-class downgrade.
• 202614 March: the Suica IC card is introduced across the whole line.