The Medieval Castle and Mighty River of Mt. Yamuki

Mt. Yamuki is a low lying peak on the banks with a huge history as a strategic location for the medieval Yamuki castle for The Mogami Clan, and for the burgeoning trade along the Mogami River that helped lead Edo, modern-day Tokyo, to its status as a global city.

Mountains in Japan have been revered for millennia, but often it is the taller peaks that garner all the attention. It’s not hard to see why, I mean, the taller peaks stick out like a sore thumb. In the case of Yamagata Prefecture, this honour belongs to the likes of Mt. Chokai, Mt. Gassan, Mt. Ide, and Mt. Zao. However, some of the low-lying peaks truly deserve a lot more attention than they get. Take the once medieval castle on the precarious cliff-face along the Mogami River that is Yamuki-yama, Mt. Yamuki, for example.

Tiny peak that was home to a medieval castle along the banks of the mighty Mogami River.
View from Mt. Yamuki. In the background are the Kamuro Alps, and you can make out the old Yamuki Trail in the snow to the bottom right.

At a humble 206m (675. ft.) above sea level, Mt. Yamuki is not breaking any records. However, this tiny peak was in one of the most strategic locations for a mountain in the entire history of Yamagata Prefecture, the banks of the Mogami River in the Motoaikai area of Shinjo City, right where the river takes a sharp turn. Mt. Yamuki’s height and location meant it was in the perfect location to oversee action from miles around, and for a river as pivotal in the development of Yamagata Prefecture, Mt. Yamuki certainly was advantageous to anyone able to lay claim to it.

The History of Mt. Yamuki and the Mogami River‌

A mountain trail up Mt. Yamuki along a thin ridge with snow blocking the path and a sign in the foreground.
The trails of Mt. Yamuki are rather thin, and in early spring still covered in snow.

‌There are two main parts of Mt. Yamuki to explore, the summit to the north, and the Yamuki castle remains on the banks of the Mogami River to the south. Built during medieval Japan (commonly referred to as the period of time between the Kamakura and Azuchi periods of 1185 to 1600), the Yamuki Castle provided the Mogami Clan expansive views over The Mogami River, a very important feature of the landscape during periods of war.

Trade on the Mogami River‌

A beech forest sans leaves with big patches of snow on the ground that mark the former location of the Yamuki Castle
The clearing where the remains of the Yamuki Castle lie.

‌This period of time was known as the Sengoku period when Japan was in a constant state of civil war. However from the 1600s onwards, Japan came under the rule of the Shogun and saw times of relative peace. During this time, trade along the Mogami River really picked up, and Mt. Yamuki was a critical landmark along the trade routes.

Known as Dewa Province at the time, this was when Yamagata Prefecture truly made its mark on the world. The development of Yamagata Prefecture is directly correlated with the early development of Edo, the city these days known as Tokyo.

How Yamagata helped Tokyo develop into an international city

You see, farmers from all over Yamagata Prefecture would send rice and safflower down the Mogami River until it reached Sakata City on the Sea of Japan coast. This rice and safflower was then traded all throughout Honshu on the Kitamae-bune North Sea Route ships. The Shogun at the time even owned land in Yamagata Prefecture and relied on the Kitamaebune ships to provide food for a burgeoning Edo.

Here’s a very in-depth, and very interesting history of the Kitamae-bune ships.

Famous Visitors to Mt. Yamuki‌

A sign on a tree along the path of Mt. Yamuki that shows the names of the surrounding mountains
A sign introducing the mountains surrounding Mt. Yamuki, such as Mt. Hiuchi-dake, Mt. Hachimori, and Mt. Mokuzo.

‌I mentioned that the cliff face was steep right? What if I told you there was a shrine located on it? Part-way up the cliff face you can make out a small red shrine, the Yamuki Shrine. The name Yamuki is from the Kami called Yamuki, and was named as such by a junior fifth rank from the government who visited in 874 during the early stages of the Heian period.

Yamuki shrine was primarily prayed to for a safe journey by people sailing on the Mogami river. One very famous person to do so was Minamoto no Yoshitsune, who stopped at this shrine specifically to pray while on his way to Hiraizumi of Oshu according to The Chronicles of Yoshitsune.

Right across the river from Mt. Yamuki was where Matsuo Basho boarded a river boat while compiling The Narrow Road to the Deep North. It is therefore very likely that he too prayed to the Yamuki Shrine.

Mt. Yamuki These Days

Mt. Yamuki in early spring. Snowy paths through a dense forest with tall snow-covered peaks in the background.
View from Mt. Yamuki. In the background are the Kamuro Alps, and you can make out the old Yamuki Trail in the snow to the bottom right.

‌Unfortunately, these days Mt. Yamuki is being slowly swallowed up by the very river that has provided so much sustenance over the centuries. The distinctive cliff face of Mt. Yamuki is becoming larger by the day, and all that remains of the castle are areas where buildings obviously lay. This means that when you visit Mt. Yamuki, you’re going to have to use your imagination a bit to get a sense for what it was like for the Daimyo throughout the years.

The Yamuki Castle isn’t that much of a hike (details below), and you can easily make out an area split into about three different heights, which were apparently the donjon, i.e. the main part of the castle, the second bailey, and the third bailey. Each bailey was said to have two defensive layers of walls called Yagenbori, with huge empty spaces between them. There was also a Noroshidai, a stand used for smoke signals.

When you get closer to the river bank, the sheer steepness of the cliff face really hits you. It. Is. Steep. Let me tell you. You do NOT want to fall down there. This also means that the views are second to none. I had never seen the Mogami winding its way up the landscape towards Oishida Town like that before. It had also never occurred to me that the river took such a sharp turn either. More than one hairpin for a fast-moving river like the Mogami would definitely mean that any mountain in its way will erode.

Getting to Mt. Yamuki

A wooden pole that signifies the summit of Mt. Yamuki and small concrete block showing its height.
Sign at the summit of Mt. Yamuki.

Good luck getting to Mt. Yamuki with anything besides a car. Heading along Route 47 from Shinjo to Tozawa Village, take a right directly in front of the Uchigawa bridge. Follow the river down a little bit and the trailhead is at the Hachiman Jinja (shrine). There is enough parking here for six cars, but be warned that it can get extremely slippery. Either make sure you have a 4WD, or park in the dry spots.

Hiking the Trail up Mt. Yamuki‌

Sign at the junction of the trail up Mt. Yamuki saying ‘100 Famous Mountains of Yamagata’ and pointing in the direction of the ruins of the Yamuki castle, and the summit of Mt. Yamuki.
A sign at the junction of Mt. Yamuki. A left will take you to the remains of the Yamuki Castle. A right to the summit.

After paying your respects at the Hachiman Jinja (in the video I mistakenly called it Yawata Jinja), follow the river to the west from the shrine and head north at the remains of the old water pump. Cross a small stream, and you’ll see signs for the trail, which begins properly here. Follow the trail for about ten minutes, and you will come across a lookout on the left hand side. Another five minutes up the mountain and you’ll reach a split in the road to either the remains of the Yamuki Castle, or the summit itself. Head north for the summit, and south for the remains of the castle.

The trail is covered in bush, and the ridge drops off sharply to the west. The remains of the Yamuki Castle are past the empty moats that were the second and third baileys. You can get a view over the Mogami river from the remains of the Yamuki Castle, but it is a sharp drop so be very careful. Also, you can get a good view of the steep cliffs of Mt. Yamuki and its spectacular mountain valley from the base of the Motoaikai Bridge on the opposite bank of the river.

Our hike up Mt. Yamuki

A post in the foreground signifying the location where Mt. Yamuki’s smoke signals were made.
A sign shows where the remains of a smoke signal stand were on Mt. Yamuki.

This seemingly easy mountain taught us a good lesson. Always check and double check you are on the right path. For the first 90 minutes, again we went the wrong way, heading up the Yamuki Kodo (八向古道 ancient path up Mt. Yamuki) instead of the more modern way.

What was supposed to be about 90 minutes one way turned into a 5 hour adventure.

It was a good adventure though, wasn’t that bad in retrospect. The first path we took was definitely the wrong way, we had to clamber on bush after bush and reed after reed only to realise that the path wasn’t really a path. So we turned back, and I’m really glad we did.

Getting on Track

Snow melts in the middle of the forests of Mt. Yamuki.

‌When we got to the entrance to the first path, we noticed that there was a gravel road that continues along the river, and then we saw a sign pointing into the mountain. If we hadn’t noticed that, I’m not sure what we would have done.

This sign pointed to seemingly nowhere, but we could make out some switchbacks in the snow that turned out to be the correct path. From then on, the path was much more obvious. A mixture of narrow gaps with snow in the middle, and then walking along sharp ridges.

Before long we reached the junction that takes you to the remains of the Yamuki castle to the left, and the summit to the right. We wanted to hit up the summit first, and kept following the path up carefully searching for the next pink marker in the trees along the way.

The trick summit‌

A clear area of land with some trees dispersed around. View of mountains in the background. This is what remains of the Yamuki Castle.
The remains of the Yamuki Castle in Shinjo City, Yamagata Prefecture. Kamuro Alps in the background.

‌There were a few areas completely inundated with snow, but we just headed in what was the right direction according to this app. After reaching what felt like the summit, we realised we still had a little further to go, and climbed up and down a few smaller peaks until we found the summit marker. 206m above sea level, with not much around it besides a beech forest.

However, we did get to see Mt. Chokai through the trees, as well as Mt. Gassan and Mt. Hayama, Mt. Maya, and then out to the Kamuro alps. On the way back I visited the remains of the Yamuki castle, which were just some flat areas of dirt, but there was a really good view over the Mogami river and the surrounding towns. All up it was very good exercise, and was a good warm up for when we hit up the Kamuro alps later, hopefully this year!

Nearby locations worth checking out

Mogami River

The sky reflecting in the Mogami River during autumn

Traveling by boat on the Mogami River

The 229km Mogami River running the length of Yamagata Prefecture is the 7th longest river in Japan, and the longest contiguous river in one prefecture, taking 3 to 5 days for the water to flow from the source to the ocean. Along with the Fuji river in Yamanashi and Shizuoka Prefectures, and the Kuma River in Kumamoto, the Mogami is one of the big three fastest-flowing rivers in Japan.

The Mogami River was featured prominently in Matsuo Basho’s The Narrow Road to the Deep North. Matsuo Basho and his trusty partner Kawai Sore stayed three days in Oishida, and once they had good weather, they travelled to the Dewa Sanzan, boarding the Mogami River in the area right in front of Mt. Yamuki.

This river voyage inspired the following haiku by Matsuo Basho:

Gathering the rains‌
‌Of summer, how swift she is‌
‌Mogami River

- Matsuo Basho

River Cruise on the Mogami

Need some inspiration? Why not do what Matsuo Basho did and take a cruise down the Mogami? River boat cruises along the Mogami are offered by multiple companies including during the cold winter months when you can sit under a heated Kotatsu and sip Amazake, a sweetened sake lees drink (the extract from making sake that is non-alcoholic).

Shiraito Falls‌

Shiraito Falls on the Mogami River
The Shiraito Falls along the Mogami River‌

Located on the opposite bank of Mogami River at the terminus of the river cruise, the Shiraito Falls is well worth a stop if you get the chance. The Shiraito Falls is one of the top 100 Falls of Japan, and it’s not hard to see why when you see the real thing.

Mt. Tsuchiyu and The Forest of Illusions: Genso no Mori in Tozawa Village‌

Genso no Mori: The Forest of Illusions in Tozawa Village
Genso no Mori: The Forest of Illusions in Tozawa Village

‌From the Shiraito Falls, Genso no Mori, the forest of illusions, is only a short drive. Or if you’re climbing Mt. Tsuchiyu, this isn’t much of a detour at all. Genso no Mori is a naturally occurring cedar forest that is covered in trees that have morphed due to the snowfall in the region. Just be warned that Genso no Mori forest can be a bit tough to get to. You have to take a sharp turn into the mountains from Route 47 along the Mogami River, and then drive up a gravel road for a while, but once you’re there it really is like being in another world.

Mt. Yonetaihei‌

Mt. Chokai stands tall above the clouds in this photo from Mt. Yonetaihei near Mt. Yamuki.

Located just to the north of Mt. Yamuki, Mt. Yonetaihei is oddly the exact same height, and is known for its marsh, the Yone Marsh. I visited Mt. Yonetaihei in winter so didn’t get to explore the marsh, but it wouldn’t be too far of a detour at all. Mt. Yonetaihei is a 30min climb to the summit too, so it would be easy to do both of these mountains in the same day (weather and season permitting).

The Totoro Trees‌

Two tress right next to each other that resemble Totoro, the loveable character from My Neighbour Totoro
This is the only photo I have of the Totoro Tree, but it really looks like Totoro!

‌With places like Ginzan Onsen and Genso-no-Mori, the forest of illusions, Yamagata Prefecture is covered in places similar to those depicted in Ghibli films, or in this case, two trees that resemble the famous character Totoro. The Totoro Trees aren’t too far from Mt. Yamuki, about 20 minutes by car.

Mt. Yozo and the Yozo marsh

One other famous marsh near Mt. Yonetaihei is the Yozo marsh found on Mt. Yozo on the borders of Sakata City and Sakegawa Village.

The Kamuro Alps

The Kamuro Alps are five or so peaks to the east of Mt. Yamuki on the other side of Shinjo City. The Kamuro Alps are Mt. Kamurosan, Mt. Komatayama, Mt. Hiuchidake, Mt. Hachimoriyama, and then Mt. Kamewariyama and Mt. Mokuzosan.

Shinjo City

Geta Pan Bakery in Shinjo

Speaking of Shinjo City, there are a lot of great places to explore here. Shinjo City is famous for its three-day festival in August, featuring huge floats and large dances that are free to watch. It is also home to one of my absolute favourite bakeries, Geta Pan (Facebook), that I intentionally go to sometimes even though it is an hour drive away.

Mt. Taizo: The Epitome of Autumn Leaves in north Japan‌

Mount Taizo of northern Japan, one of the best spots to view the autumn leaves, covered in all manner of colours, featuring deep reds, yellows, and greens and Susuki grasses in the foreground with a bright blue autumn sky in the background.
The autumn leaves at the summit of Mount Taizo

Mount Taizo is one of the historic routes linking The Shonai and Mogami Regions of Yamagata Prefecture, and is by far one of the best spots in Tohoku, North Japan, to take in the autumn leaves.

Mt. Yamuki | 八向山| やむきやま‌

Mt. Gassan seen from near the summit of Mt. Yamuki‌

Mt. Yamuki is Known for:

  • Location of the medieval Yamuki Castle on the banks of the Mogami River
  • Grand views over the Mogami River and to Mt. Gassan, Mt. Hayama, The Kamuro Alps, and Mt. Chokai.
  • Location of Yamuki Shrine prayed to by millions over the years, including Minamoto no Yoshitsune
  • Location Matsuo Basho boarded the Mogami River on his way to the Dewa Sanzan

Mt. Yamukiyama (八向山やむきやま) is a 206m (675. ft.) peak in the Mogami region of Yamagata prefecture. Mt. Yamukiyama is open from April to October. Mt. Yamukiyama is a level 1 in terms of physical demand, which means it is easy to hike, has a A technical grade, which means it requires little expertise, and you want to allow at least 2 hours for a climb.

Mt. Yamuki Map

Mountain Range: Mt. Yamuki (Yamukiyama)

Region: Mogami

Elevation: 206m

Technical Demand: 1

Physical Demand: A

Trails: 1)

Climbing Season: April to October

Day trip possible? Yes,

Minimum Time Required: 2 hours

100 Famous Mountains of Yamagata Peaks

  1. Exploring The Yamabushi Trails of Kinbo-zan
  2. Sakura Mountain: Arakura-yama
  3. Whetting your appetite for wetlands on Takadate-yama
  4. The Hidden Side of Haguro-san (Haguro Kodo)
  5. The Shogun and the Falcon, How I “Conquered” Japan: Nihon-koku
  6. Dancing in the Dawn Lillies: Shoga-dake and The Fuji of The North
  7. Bananas and Cokes, Leaches and Pit Vipers: Kumanonaga-mine
  8. Reaching Peak Tranquility on Atsumi-dake
  9. Sanze’s Little Helper: Fujikura-yama
  10. The Dewa Sanzan’s “Mountain of Death” — Gas-san
  11. The Dewa Sanzan’s “Mountain of Rebirth” — Yudono-san
  12. Womb Passes and Monkey Crossings: Kyogakura-yama — The Shugendo Peak of Sutras
  13. Mythical Beasts, Buddha’s Mother and Buried Yamabushi Treasure? Welcome to Maya-san
  14. The Widow’s Peak: Ubaga-take
  15. The Epitome of Autumn Leaves in North Japan: Taizo-san
  16. Mother. Hunter. Mountain. Hokari-yama
  17. Homer Simpson’s Heaven in North Japan: The Donut-shaped Yonetaihei-zan
  18. The Medieval Castle and Mighty River of Yamuki-yama
  19. Panoramas and picnics under the Sakura: Kita-yama
  20. Yozo-san: White Snakes, White Monkeys and Slimy Salamanders
  21. Abandoned Ski Field and Phantom Forest of Tsuchiyu-yama (Mt. Tsuchiyu)
  22. Turtles, Tigers, and a Legendary Japanese Character: Kamewari-yama
  23. Zao-san and Why We Climb Mountains
  24. Japan Has Pyramids? — Yakushi-san and The OG Japan content creator
  25. Venerable Old Man Mountain — The Mist and Mystery of Okina-san


Yamagatayama Page (Japanese):

Yamuki Castle and the Basho River Boats (Japanese):八向(やむき)楯と芭蕉乗船の地
八向楯は、新田川が最上川に注ぎ込む河口にあり、最上川の雄大な流れに白い絶壁が映え絶景です。 俳聖芭蕉と曾良が舟に乗って最上川を下ったのがこの辺りで、「芭蕉乗船の地」として芭蕉と曽良の陶像が立っています。…

Yamuki Shrine (Japanese):



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