Oze — Hatomachi Pass

photo by Σ64 · CC BY 3.0

photo by Σ64 · CC BY 3.0

At 1,591 m, an hour's walk from the largest marsh on Honshū: 849 hectares at 1,400 m.

The pass, at 1,591 metres, is the most widely used starting point for Ozegahara, the largest high-altitude marsh on Honshū (849 hectares at about 1,400 metres), inside a national park that split off from Nikkō National Park in 2007. After about an hour's walk downhill on wooden boardwalks you reach Yamanohana and the marsh proper; the mizubashō (a marsh plant with a white spathe) flowers from late May to mid-June. From 17 April to 5 November 2026 private cars are banned on the last stretch: you leave the car at the Oze Daiichi car park, in Tokura, and go up by shuttle bus.

Oze is a marsh that spans the prefectures of Gunma, Fukushima, Niigata and Tochigi, inside a national park created in 2007 by separating the area from Nikkō National Park. On the Gunma side you reach it from Hatomachi Pass, 1,591 metres, where the road ends in an open area with mountain huts and shops. From there a path of wooden boardwalks descends in about an hour to Yamanohana, 1,410 metres, and to the Ozegahara marsh, 849 hectares of peat bog where the mizubashō grows (the yellow part in the centre of the flower is the real flower, the white leaves around it are a modified spathe) between late May and mid-June. To protect the environment, from 17 April (10:00) to 5 November 2026 (14:00) the stretch between Tsunaki and the pass is closed to private cars: you get there by shuttle bus from the Oze Daiichi car park, in Tokura.

ℹ️ The road to the pass is closed to private cars from 17 April (10:00) to 5 November 2026 (14:00): you park at Oze Daiichi (Tokura, 280 spaces, 1,000 yen/24h) and take the shuttle bus, 1,300 yen adults / 650 yen children each way, running from 18 April to 3 November 2026. In any case the pass is impassable in winter because of snow; check the seasonal closure dates. The path to Ozegahara requires hiking shoes; the mizubashō flower contains calcium oxalate and can irritate the skin, so it must not be touched.

🚉 鳩待峠 · 1 min walk

Sources: vill.katashina.gunma.jp · pref.gunma.jp · tobutoptours.jp

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