Mt Koasama (1655m) & The Shinano Nature Trail, Karuizawa Town, Nagano Prefecture, Saturday, November 5, 2022

Hiking with the Tokyo Wide Pass

Hiking in the Joshin-Estu Kogen National Park

上信越高原国立公園

View towards the Nishi-Joshu mountains

Autumn colours were at their peak on the Shinano Nature Trail

This was the second of two hikes using the Tokyo Wide Pass. On the first trip, I went to Shiobara. This time, I decided to visit the Karuizawa area; I created my own hike, since I couldn’t find anything suitable near a shinkansen station in my hiking books. I would ride a bus to the east side of Mt Asama, go up and down a small protrusion there (I did one on the south side during Golden week), and then follow the Shinano Nature Trail back to the outskirts of Karuizawa town; on the way, I would pass by the Shiraito Falls. It was my first time to visit Karuizawa in November, and although I was concerned about crowds, I was looking forward to seeing its beautiful autumn colours.

View of Mt Hanamagari (left) and Mt Myogi (right)

View of Mt Asamakakushi (left) and Mt Haruna (center)

It was overcast and cold when I reached the start of the trail near Mine-no-Chaya (峰の茶屋) at 11am, after a 30 minute bus ride from the station. At 1400m high, autumn was already over. I followed a gently rising trail through leafless birches up the side of the miniature volcano. Very soon, I was scrambling up the exposed, rocky summit cone, and just before noon, I was standing on top of Mt Koasama (小浅間山 こあさまやま koasamayama). The name means “little Asama” and turning around, I could see the much bigger summit cone of Mt Asama opposite, its tip already covered with specks of snow.

View of the eastern side of Mt Asama from Mt Koasama

Trail for Mt Koasama (left) / The Shinano Nature Trail (right)

I had a glorious view of the surrounding forest, forming a multicolour patchwork of red, orange and yellow. To the south, I could see the mountains of Nishi-Joshu fading into the midday haze, although the jagged top of Mt Myogi was clearly visible. After enjoying the panoramic view, I retreated to the relative warmth of the forested lower section. By 1pm, I was at the start of the Shinano Nature Trail (信濃自路然歩道 shinanoji shizen hodo), just a few minutes from the base of the mini-volcano. It felt even colder than before, and I was surprised to see a few snowflakes float down from the sky.

Yellow larches along the Shinano Nature Trail

A relaxing hike along the side of a river valley

I followed a well-maintained and easy to hike trail through a wintry white-birch forest (白樺 shira-kaba), and after descending a series of log steps, reached the the Shiraito Falls (白糸の滝 shiraito-no-taki, meaning “white thread”). There were quite a few people here so I didn’t linger. I continued along the trail, as it followed the side of a narrow river valley, occasionally crossing the water over small wooden bridges, the sound of rushing water always in the background.

The Shiraito falls, the highlight of the Shinano Nature Trail

Walking next to a river (left) / Walking among the autumn leaves (right)

I was surrounded by towering yellow larches, and it felt like autumn had suddenly returned. At 3pm, I took a break at Ryugaeshi no taki (竜返しの滝), a few minutes off the main trail. As the hiking path gradually descended, the trees regained their colours and the sunlight burst through the clouds. I met few other hikers, and after another hour of relaxing and peaceful hiking, arrived at the Mikasa (三笠) bus stop. There, I caught a bus just after 4pm for the short ride back to Karuizawa station, where I boarded the shinkansen for the one-hour trip back to Tokyo.

See the views from the top of Mt Kosama and along the Shinano Nature Trail

See a slideshow of more photos of the hike