Mt. Kasamaruyama

Mt. Kasamaruyama (笠丸山, 1,189 m) is a mountain in Uenomura, Tano District, Gunma Prefecture, and one of the 100 Famous Mountains of Kantō. A rocky-ridge peak of western Jōshū, it has rope- and ladder-equipped crags near the summit. From mid-April to early May it is known as an azalea spot where Akayashio, Mitsuba-tsutsuji and Hikage-tsutsuji bloom, and from the top there is an all-round view to Mt. Ryōkami and the peaks of western Jōshū and the Jōshū–Bushū border.
Uenomura has little public transport, so access to the Sumaizuku trailhead on the eastern foot is realistic by private car or taxi.

Mt. Kasamaruyama is one of the 100 Famous Mountains of Kantō (and one of the 100 Famous Mountains of Gunma). The Sumaizuku trailhead, reached by a forest road along the Sumaizuku valley from central Uenomura, is the starting point, and a counterclockwise loop is usual — about 3 hours in all. Public transport does not reach the trailhead, so a private car, a shared taxi or a taxi is required.

*Timetable last checked: unverified

1. [Outbound] Uenomura → Sumaizuku trailhead (car / taxi) → Kasamaruyama
2. [Return] Kasamaruyama → Sumaizuku trailhead (loop)
3. Recommended plans & area info

1. [Outbound] Uenomura → Sumaizuku trailhead (car / taxi) → Kasamaruyama

As no public transport reaches the Sumaizuku trailhead, go by private car (a parking area for 8–10 cars sits just before the trailhead) or by taxi or Uenomura’s reservation-based shared taxi. From the trailhead, climb along the valley, cross Jizō Pass, and reach the rocky ridge, then ascend with the help of ropes and ladders to the summit of Kasamaruyama — about 1 hour 30 minutes from the trailhead. The summit has an east and a west peak with the open views typical of western Jōshū. Crags and knife-edge ridges continue, so move carefully.

Reference: Uenomura Village

2. [Return] Kasamaruyama → Sumaizuku trailhead (loop)

To descend, drop from the west peak along the ridge and return to the Sumaizuku trailhead via the Jizō Pass junction — the whole loop is about 3 hours. There are rocky descents and knife-edge ridges, so stay alert on the way down too. Back at the trailhead, drive or take a taxi to central Uenomura. There are no shops or water sources on the mountain, so prepare food and water in advance.

Reference: Jōmō Shimbun — Gunma mountain walks, Kasamaruyama

3. Recommended plans & area info

Loop plan: Sumaizuku trailhead → Jizō Pass → Kasamaruyama (east & west peaks) → Sumaizuku trailhead (about 3 hours). An intermediate-to-advanced course with continuous crags, and a representative azalea mountain of western Jōshū.
Best season: mid-April to early May, when the Akayashio bloom, is ideal; Mitsuba-tsutsuji and Hikage-tsutsuji are also seen. With so much rock, avoid the mountain in rain or icy conditions.