Naeba-Sanroku Geopark Tsunan Ultramarathon 48K

Race completed

48 km Distance

2,800 m Climbing

6.6 Grit · Hardcore

37.0143° N, 138.6525° E © OpenFreeMap © OpenMapTiles Data from OpenStreetMap

What the course asks

Climbing rate 58 m / km Mountain. Significant climbing. Steep sections will require power hiking.

Time limit 15 hours 18:45 min/km average. Generous. Walkable throughout for most of the field. Among the most forgiving 50K cut-offs we track. Measured against 984 races of the same distance. Cut-off calculator →

Field size ~72 Mid-sized. Company early, well spread out by halfway.

DUV results for the 2026 edition (48km) — finishers only. Starters are not published, so the field was at least this big and no finish rate can be given.

Typical conditions, July

Daytime high 26°C

Night low 17°C

Rainfall Wet — expect rain

Daylight 14 h 38 m of light

Regional 2001-2020 average for July — NASA POWER, grid elevation 784 m. Not a forecast.

The Aid Station

Course-specific beta from the community

⛰️ terrain

This is a mountain course. Poles are highly recommended for the sustained climbs.

By UltraHub Expert

👟 gear

With road terrain, choose a shoe with moderate cushioning for optimal performance.

By UltraHub Expert

Gear for this race

Chosen for 48 km of road with 2,800 m of ascent.

Trail Running Shoes 58 m of climb per kilometre — grip and rock protection before cushioning.
Race Nutrition 48 km of self-supported fuelling between aid stations.
Hydration Vests Pole attachment and chest-strap stability on steep ground.
Trekking Poles 2,800 m of ascent to walk up.
Headlamps A 15 h limit puts you out there after dark.