Former JNR Shihoro Line

The Former JNR Shihoro Line

The Former JNR Shihoro Line (旧国鉄士幌線) is the remains of a railway that ran north through Kamishihoro, Kato District, Hokkaido, and nine of its concrete structures built between 1936 and 1955, seven bridges, a tunnel and a station platform, are registered as Registered Tangible Cultural Properties (Agency for Cultural Affairs). All nine are owned by Kamishihoro Town.

The town's own chronology traces the line north from Obihiro: it reached Shihoro in December 1925 and Kamishihoro on July 1, 1926. Beyond that the track pushed into the hills in stages, to Shimizudani in November 1935, to Nukabira on September 26, 1937, and to Tokachi-Mitsumata on November 18, 1939.

The Agency notes that the Kamishihoro to Tokachi-Mitsumata section was built as the Otofuke Line and that the Shihoro Line was meant to link Obihiro with Rubeshibe. The section climbed the Otofuke River valley, and many of its river and stream crossings were built as concrete arches.

Rerouting and Closure

In 1955 the track near Nukabira was rerouted (Agency for Cultural Affairs). Two of the nine registered structures, the Nukabira River and Sannosawa bridges over streams feeding Lake Nukabira, were built for that new alignment. The old line went under the lake, where the Taushubetsu River Bridge rises above the water or disappears depending on the level; that bridge is not among the registered structures (Hokkaido official tourism site).

Kamishihoro Town records that trains between Nukabira and Tokachi-Mitsumata were replaced by buses on December 25, 1978, and that the Shihoro Line itself closed on March 22, 1987.

Bridges Taken Over by the Town

About a decade after closure, demolition of the abandoned bridges began; by March 1997 the Fourth Otofuke River Bridge was being taken down. Kamishihoro Town bought the arch bridges and the old trackbed on October 7, 1998, and took over the Sixth Otofuke River Bridge in February 2002 (Kamishihoro Town).

The structures were registered in three rounds (Agency for Cultural Affairs):

• August 23, 1999: Isamigawa, Third Otofuke River, Fifth Otofuke River and Jusannosawa bridges
• January 31, 2003: Sixth Otofuke River Bridge and Otofuke Tunnel
• June 28, 2017: Nukabira River Bridge, Sannosawa Bridge and Horoka Station Platform

The arch bridges were also chosen as a Hokkaido Heritage on December 15, 2001 (Kamishihoro Town).

Where the Nine Structures Are

The nine sites follow the Otofuke River from south to north, roughly along National Route 273. From the end nearest Kamishihoro town, they fall into three clusters (by the addresses held by the Agency for Cultural Affairs):

• Southern group, in the 黒石平 district: Isamigawa Bridge and Third Otofuke River Bridge
• Nukabira Gensenkyo: Nukabira River Bridge and Sannosawa Bridge
• Horoka: Otofuke Tunnel, Horoka Station Platform, Fifth and Sixth Otofuke River bridges, Jusannosawa Bridge

The Jusannosawa Bridge, furthest north, stands close to the old terminus at Tokachi-Mitsumata (Agency for Cultural Affairs). The scale varies a great deal, from the Isamigawa Bridge at 4 metres overall to the Fifth Otofuke River Bridge at 109 metres. Each structure has its own page.

Visiting and Getting There

According to the Hokkaido official tourism site, Nukabira Gensenkyo, the hot-spring village in the middle of the line, is about 80 minutes by car from Otofuke-Obihiro Interchange on the Doto Expressway and about 90 minutes from JR Obihiro Station. Enquiries go to the Kamishihoro Town tourist information office (01564-4-2224).

All nine are outdoor engineering works and there is no charge to see them. Only some of the bridges can be walked across, and others are closed to foot traffic on the deck (Hokkaido Fan Magazine). Follow the signs on site and stay behind fences and barriers.

This is brown bear country, and visitors to the Horoka station site are reminded to take care (Nippon Tabi Magazine). Be especially careful when leaving the highway for forest roads or stream banks.

The Kamishihoro Town Railway Museum, on the site of Nukabira Station, displays photographs and material from the Shihoro Line (Nippon Tabi Magazine). A stop there first makes the layout of the nine sites much easier to follow.