Atlas › Tanigawa-renpo (Gunma)
Narumizu-sawa
verified
Ungraded
High flood risk
Minakami, Gunma
Emerald pools, kilometer-long slabs, and a meadow exit onto the Asahi-dake ridge. The classic Tanigawa overnight sawanobori.
Often paired with East Kurosawa (Higashi-Kurosawa) as the approach drainage, with descent back down East Kurosawa to close the loop. The 'Tokyo kiten sawanobori route 120' guidebook lists this as one of the marquee Tanigawa lines. Parties typically bivy below the upper waterfalls and finish over the ridge the second day. Snowfields linger into June and turn the upper slabs into a postholing slog; mid-July onward is the honest window.
Logistics
| Manager | Joshinetsu-kogen NP, Forestry Agency |
|---|---|
| Permit | No permit required. Mountain plan (tozan-todoke) recommended with Gunma Prefectural Police; standard practice for any backcountry sawanobori party. |
| Distance | ~8 to 10 mi total loop with East Kurosawa approach |
| Elevation | ~2,000 ft gain to the Asahi-dake ridge |
| Time | 1 to 2 day overnight |
| Technical | Classic intermediate sawanobori in the Okutone region. Approach via Higashi-Kurosawa (East Kurosawa), a soothing run of slabs and short waterfalls including Hanage-no-taki climbed on the left. Main line up Narumizu-sawa features emerald plunge pools, long nameshou slabs, an S-curved gorge, and Uodomari-no-taki bypassed right at high flow. Sawanobori grade 2 (intermediate). Exits onto Asahi-dake ridge with a meadow finish (the 'tengoku-no-tsume', heaven's pinch). |
| Season | Mid-July to early October. Snowmelt persists into late June. |
| Flood risk | High. The Tanigawa massif draws heavy thunderstorms; the slot funnels everything off Asahi-dake and Shichikoyayama. Cancel on any forecast rain in the upper drainage. |
| Vehicle access | 2WD paved to the Shiraga-mon trailhead via Tochibora Onsen. |
| Crowd | Moderate. The most-trafficked overnight sawanobori line on the Gunma side of Tanigawa. |
| Coordinates | 36.859, 138.946 |
Sources
- guide operator: https://tocotoco-m.net/2025/08/21/narumizu-sawanobori/
- guidebook ref: https://www.yamakei.co.jp/products/2815120459.html
- route: https://sawagurui.com/narumizusawa