OSJ Okukuji Trail 59 km 2025
Set in the Okukuji hills of northern Ibaraki. From Fukuroda Onsen the course crosses the ridges around Fukuroda Falls and Mt Nantai to the Ryujin Suspension Bridge, loops through Hitachiota and returns via Mochikata village. Relentless ups and downs; 2025 was the 15th edition.
The course tops out at 634 m (low point 88 m). There are 3 big climbs: 533 m around 0–10 km; 313 m around 37–45 km; 321 m around 46–48 km. About 30% of the distance is gentle (under 5% grade). In 2025, 55% of starters finished — a tough one. The median finish was about 12 h.
Estimate your finish from your ITRA index
Estimate (no finisher data for this race)
Enter your ITRA performance index to get an estimated finish time, aid-station splits and cutoff margins. This race has no finisher ITRA data, so it uses the transfer model: your predictions for the 205 races that do have finisher data, scaled by distance and elevation gain (km-effort) — the same calculation as the TRAIL STATUS app. Nothing is saved or sent.
The app adds predictions from your training log (Strava), race-day pacing and more. Free, no sign-up.
Predict in detail from my Strava trainingOverview
- Date
- Sun, 25 May 2025
- Start
- 05:30
- Location
- Ibaraki, Japan
- Distance
- 59 km
- Elevation gain
- 3,550 m
- Time limit
- 14h 30m
- ITRA
- 50M
- Official website
- www.powersports.co.jp/osjtrail/25_okukuji/race.html
Elevation profile
Aid stations and cutoffs
| # | Distance | Aid station | Segment | Cutoff |
|---|---|---|---|---|
| 1 | 9.5 km | Aid 1持方（第1関門） | 9.5 km | Day 1 09:003h 30m |
| 2 | 26.5 km | Aid 2竜神大吊橋（第2関門） | 17 km | Day 1 12:307h |
| 3 | 40 km | Aid 3竜っちゃん乃湯（第3関門） | 13.5 km | Day 1 14:309h |
| 4 | 52.5 km | Aid 4持方（第4関門） | 12.5 km | Day 1 18:0012h 30m |
| F | 59 km | FinishFINISH 袋田温泉 | 6.5 km | Day 1 20:0014h 30m |
The small figure under each cutoff is the time from the start. Day 1 is the day of the start.
2025 results
328 starters, 180 finishers (54.9% finish rate). Finish times of those who finished:
- Fastest
- 7h 53m
- Top 10%
- 9h 14m
- Top 25%
- 10h 31m
- Median
- 11h 52m
- Top 75%
- 12h 37m
- Top 90%
- 13h 20m
- Last finisher
- 14h 17m
"Top 25%" means one in four finishers had crossed the line by this time.
Years with a different course or different cutoffs are not directly comparable.
Practice courses
See the course on the Runnable map ↗
Runnable has practice courses on this race's trails, split into sections to run and sections to walk (pages in Japanese).
- Runnable practice course (53.2 km)
Other races
- OSJ Okukuji Trail Short 32.5 km 2025Sun, 25 May 2025 · Ibaraki, Japan · 32.5 km
- Tsukubarenzan trailrun in ISHIOKA 70 km 2026Sun, 27 Sep 2026 · Ibaraki, Japan · 70 km
- Tsukubarenzan Middle 45 km 2026Sun, 27 Sep 2026 · Ibaraki, Japan · 45 km
- Tsukubarenzan Short 25 km 2026Sun, 27 Sep 2026 · Ibaraki, Japan · 25 km
- BULSS 茨城 (Backyard Ultra Last Samurai Standing) 2026Sat, 7 Nov 2026 · Ibaraki, Japan
- NOZAWA 65 km 2026Sun, 19 Jul 2026 · Nagano, Japan · 65 km
From your training log, TRAIL STATUS estimates your finish time, aid-station splits and cutoff margins for this race.
Predict my raceCompiled from each race's official information. Details can change, so always check the race's official website for the latest. Spotted a mistake? Please tell us through the contact form.
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