“Restoring Beauty: The Mountain’s Transformation with Every Visitor” —The approach and future of trail maintenance in Hakone using the ecological restoration method.

The deterioration of mountain trails is now being discussed as a nationwide problem. In this context, a maintenance method that focuses not only on mountain trails but also on the ecology of the mountains at large has been attracting attention. How should mountain trails be repaired, and how should we, as mountaineers, deal with the mountains? We joined a workshop to learn about reconstructing the trail based on the ecological restoration method, developed from the neo-natural river reconstruction method, to figure out some answers to these questions.

The light-weight truck was filled with large logs collected from the neighborhood the day before. The two-meter-long logs must have weighed more than 40 kg each. The logs were intended to be transported to the site, but their sheer size made everyone hesitant. The man then tied a log to a well-used carrier. He smiled and pulled the sling over his back, mentioning that he used a thick, old-fashioned sling because a thin Dyneema sling would dig into his body. Surprised at how effortlessly he handled it, I attempted to carry it on my back, but my spine creaked, and my legs felt wobbly. Not only was it heavy, but the length of the log, different from a backpack, compromised the stability of my feet. I was told that in the local Daisetsuzan mountains, they sometimes carried over 50 kg of logs and walked 4 km of a mountain path.

“Now, let’s go!”

Tetsuzo Okazaki of the “Daisetsuzan Mountain Guard” shouts as he picks up his favorite hammer weighing 0.9 kg. Tetsuzo travels around Japan to pass on the techniques he has developed in Daisetsuzan for mountain trail maintenance using an ecological restoration method based on the neo-natural river reconstruction method. He also shares knowledge on creating a sustainable mountain management system.

Hakone in Kanagawa Prefecture features a distinctive landscape sculpted by volcanoes and a rich history and culture as an inn town along the Tokaido Highway. As one of the most popular tourist destinations, drawing in 20 million visitors annually, it is also renowned as a mountaineering town. Mt. Kintoki (1,212 m), one of the Three Hundred Famous Mountains of Japan, known for its breathtaking views, is situated here. A circular course around the outer ring of mountains, including Mt. Kintoki, is favored by trail runners. Furthermore, the Old Tokaido Highway along the Sukumo River still features stone cobble paths from the Edo period, offering a glimpse into the atmospheric mountain journey of the past. The diverse appeal found in Hakone accommodates various styles of mountaineering and attracts climbers, making it a popular destination.
Hundreds of thousands of people visit the Hakone mountains yearly, causing the trails to develop V-shaped indentations due to soil trampling and water runoff caused by heavy rain. “While it is not impossible to walk on the trails, we couldn’t leave them in this state. Therefore, we have been working on improving the trails for the past 20 years or so,” Kazunori Kato of the Hakone Visitor Center remarked.
He shared with us that the tourist association of Hakone Town, which is responsible for managing the trail, and the Nature Conservation Center of Kanagawa Prefecture have played a central role in the maintenance of the trail, regularly inviting volunteers twice a month to assist. “When it comes to the balance between trail use and trail maintenance, the former constitutes by far the greater proportion,” says Akira Tsujimoto of the Kanagawa Prefectural Nature Conservation Center. Akira has not only been involved in trail conservation in Tanzawa and Hakone as a prefectural official but has also established a ‘Restore Team’ with fellow volunteers. He has worked for many years to repair trails in Hakone and eliminate specific invasive alien species.
The connection between Hakone Town and Tetsuzo Okazaki was facilitated by the sports apparel manufacturer GOLDWIN, which houses The North Face and other brands. Equipped with extensive knowledge of domestic and international fields, outdoor spirit and culture, and environmental conservation, they have entered into “Comprehensive Cooperation Agreements” with various municipalities, aiming to revitalize local communities with such expertise. The agreement with Hakone Town was concluded in 2022, and since then, the company has been supporting diverse initiatives set against the backdrop of Hakone’s nature.
“Trail maintenance poses a national challenge. We wondered if there was an approach that repaired and revived nature. That’s when we learned about Tetsuzo’s project and extended an invitation to him in Hokuto City, Yamanashi Prefecture, with whom we share a similar comprehensive cooperation agreement. The purpose was to seek guidance on trail maintenance using the ecological restoration method,” says Takeshi Moto of The North Face. Hokuto City, which agreed with Tetsuzo’s activities and sentiments, has established the “Hokuto City Mountain Guard Team” to encourage the restoration of mountain trails and the environment using the ecological restoration method. The initiative aims to promote the enjoyment of preserving their beloved local mountains. He continues, “Given such background, two years ago, I proposed that Hakone Town collaborate with Tetsuzo’s mountain trail maintenance, which is based on the ecological restoration method.”
Hakone Town has been conducting trail maintenance for many years, and both Tetsuzo and Takeshi expressed concerns about how this new method will be accepted. Despite this concern, the training course on the ecological restoration method was enthusiastically embraced by Hakone Town, leading to Tetsuzo being invited back on the 15th and 16th of November, 2022. On this day, 18 individuals gathered, including members of the maintenance team, regular volunteers, staff from the tourist association and Hakone Town, local guides, and GOLDWIN employees, all of whom deeply care for the mountains of Hakone. On the 15th, they collected the logs needed for maintenance work near the repair site, and the training on the 16th began with an indoor lecture.

“Like the Daisetsuzan, the Hakone mountains were covered with vegetation before people started walking on them. In that state, rainwater would have been dispersed by the plants and flowed over the ground surface. As people began to walk there, the stems collapsed due to tread pressure, further leading to bare ground. This is how many of our trails came into being,” Tetsuzo explains.
Once the ground surface is exposed, further trampling pressure causes the path to become a depression, and every time it rains, it erodes and becomes a gully, providing a path for strong water currents. When deep gully landforms (V-shaped scarped landforms) are formed this way, erosion accelerates and becomes an unstoppable vicious circle, regardless of whether people use the path. Climbers avoid walking through the gullies, so the bare ground spreads to the surrounding area. Tetsuzo continues. “This is why maintenance becomes necessary, but what I want you to think about here is what you are trying to achieve by fixing the trail.”
What is the purpose of trail maintenance? To facilitate easier passage on trails that have become difficult due to spills and collapses. …? “Generally, yes. However, without examining the causes of the trail collapse, constructing features such as steps can contribute to additional soil erosion.”
When erosion is caused by running water, if structures that are harder than the soil are placed without drainage treatment, the erosion will spread to weaker areas, bypassing them. This is why the space between steps and under steps is eroded. “The first action is to remove the causes of erosion and mitigate the changes that occur in nature.”
Here, two photographs are displayed on the slide: one of the trail where the V-shaped gully landform has been cut down to bare ground and another photograph of the trail a few years after it was restored. It has been raised, and the surrounding area is covered with green vegetation. “Of course, when it rains, water flows over the trail, but by raising it and widening the area of the water path, the flow is slowed down. And even then, the construction is designed so that the sediment that still flows will accumulate in the right places and stabilize. When the soil is stabilized in this way, vegetation is restored, as you can see here.”
As plants and trees flourish and take root, the soil becomes stronger. In other words, the restoration is done so that nature’s regenerative capacity can function properly.
In the next photograph, taken 18 years later, the entire trail is covered with greenery, and it is difficult to tell where the work has been done. “The purpose of the trail maintenance, as I mentioned earlier, is not to ‘restore convenience for climbers’ but to ‘restore the ecosystem’,” Tetsuzo says.
Tetsuzo believes that trail maintenance is about nurturing the landscape. It involves envisioning nature before human intervention, accurately understanding the terrain and geology of the site, and creating an environment where the plants supporting the base of the ecosystem can be restored. In other words, the objective is to rejuvenate and maintain trails where nature is prioritized, not for the sake of humans, but to preserve the natural environment. “I believe that we climbers climb mountains not because there are easy paths to walk on but because we want to encounter wonderful nature. Let’s keep the coexistence of people and nature as our theme and continue maintaining the trails.”

After the indoor lecture, it was time for practical application. The group headed to the maintenance site near the summit of Mt. Marutake (1156 m), part of the outer rim. A trench-like landform about 1.5 meters deep and extending for about 15 meters could be seen there. The goal here is to raise the V-shaped, eroded, and bare mountain trail to the height where plants thrive on both sides of the slope. The plant-covered slopes will resist erosion, and by elevating the narrow valley floor to broaden the base, the flow of rainwater can be gently controlled.
First, the transported logs were assembled in a continuous Z-shape at the height of the side slopes, covered with vegetation. Instead of using stakes to secure the logs, natural materials such as rocks and tree roots on the slopes were skillfully utilized. However, a question arises here: Why aren’t the logs arranged parallel to the mountain trail? “When logs are laid out parallel to each other, the water coming from upstream falls straight down in a vertical direction. But by making a Z-shape, we can divert the water flow and make it flow over a longer distance, thereby reducing the force of the water,” Tetsuzo replies.
Tetsuzo told us how he closely observes the formation of mountains and streams. He examines how a vigorously flowing stream can navigate its surroundings without causing disruption and how it gracefully flows while maintaining its momentum. By closely observing nature, it provides valuable insights. However, when people attempt to create something, they often fixate on “parallel and evenly spaced” arrangements. In the natural world, things are never arranged at the same angles or shapes. Moreover, continuity in nature that is too regular can create a sense of discordance.
That’s why he looks at the site carefully and weaves out heights and angles that fit in with the surroundings. “Those who can do it intuitively are artists, but I am not an artist. So, I observe closely and reflect on the environment. While what I create is sometimes labeled artistic, it involves careful planning. Nevertheless, I can understand how true art connects with nature.”
This is probably one of the challenges in communicating the ecological restoration method. Training the eye to observe the ever-changing nature, imagining its form several years later, and aiming to restore it as close as possible to its original state is a painstaking task. Additionally, for the envisioned mountain trail to materialize, one must wait for the recovery of the ecosystem. Since we are dealing with nature and working alongside it rather than trying to tame it, achieving quick results is impossible.
However, the discord within nature was evident even to the untrained eye. The fallen tree used for log reinforcement caught the group’s attention, prompting shared attention. In response, one participant reached out and adjusted the angle. Tetsuzo showed a contended look.
The next task was to fill the space under the logs. The optimal way to do this is to use earth and sand that were originally there and had run off. However, the space was filled with fallen trees and wood chips from the nearby area on this day. Additionally, thin branches were used to fill the gaps between the trees.
“Although you might be concerned about the wood buried inside, xylophagous fungi are aerobic organisms, so when deprived of oxygen, their activity diminishes. In places like Yakushima, artisans have turned buried timber from the Edo period into crafts. The reason the material hadn’t decayed is also due to the same principle.”
Finally, fallen leaves and soil are placed slightly higher than the logs. It will settle at just the right height when firmly packed down. “Even when constructed in this way, the overall structure will gradually sink over a long period. Even so, they maintain their height by catching and holding the sediment that flows down from above in the rain, so they don’t collapse suddenly and significantly.”
After three hours of work, the 15-meter gully was beautifully restored, and the trail, constructed from ten logs, blended in so well with the surrounding landscape that it was hard to believe it had only just been built. We all took a commemorative photograph. Everyone’s flushed faces showed a sense of fulfillment.

The trail was transformed after three hours of work by 18 people. We cannot wait for the beautiful flowers to bloom.

Once the work was completed, a concluding discussion took place. According to Tetsuzo, having this kind of time after work is unusual. The enthusiasm of the Hakone mountaineers is evident despite their fatigue.
As many participants were already involved in trail maintenance, the discussion was full of technical talks. Some mentioned that having a large group today was beneficial while acknowledging the challenges with fewer people. However, Tetsuzo smiled and remarked, “If you think about how to accomplish today’s tasks alone or with a smaller group, you will naturally identify what needs to be done.”
After addressing the technical questions and challenges, Tetsuzo said, “we repaired the trail using the ecological restoration method, but this is not the only way to improve the trail.”
There are 300 kilometers of trails on Daisetsuzan, where Tetsuzo works hard. Maintenance is only possible during the three-month snow-free season from June to September. The trails are diligently repaired during this time, covering 20 to 30 meters daily. Simultaneously, many mountaineers enjoy their hikes. Even if ten negative impacts need attention, only one or two can be restored; with the lack of workforce, the negative impact gradually accumulates. The ecological restoration method provides a sense of accomplishment in the hands-on work and instills confidence that it leads to the future. Despite the profound satisfaction from the work, Tetsuzo is clear that merely fixing what you want in your own way without addressing the overall issues is nothing more than self-satisfaction. He adds, “I want you to consider the overall approach to managing the mountains.”
The mountain environment can only maintain its stability if there is a sustained and manageable system for trail maintenance, ensuring a balance between the degradation and restoration of trails. How can we transition from the current situation at minus 8 to a state closer to zero negative? “To conserve the mountain, we must first understand the current situation. Then, we can share the challenges and formulate a vision. It is only after that that we consider the means of construction.”
National parks in Japan, for example, do not have such a system in place, partly due to a lack of management personnel. As a result, they are unable to grasp the current situation of where and how the trails need repair. “In the midst of all this, many of Hakone’s trails can be approached by car, and there are so many people who are passionate about their maintenance. In addition to the enthusiasm of the town and the tourist association, even companies are supporting the project. I think Hakone has the potential to become a model case for mountain trail maintenance.”
Finally, what should we climbers do? Every step we take is impacting the mountains we love. “The first step is to encourage people to become aware of that. Like guides, we want people to walk safely, so if there is a slope with fewer steps than the trail, we lead them that way. But when mountaineers realize that the accumulation of these steps is destroying the trail, they change how they look at the trail and the mountain. The sentiment of ‘I want to restore the trail’ arrives afterwards. If more people realize this, we can turn the negative state from six to five just through the movement of climbers.”

Text=Koki Aso
Photo = Reishi Eguma
Translation = Asaka Barsley
Interview cooperation = Daisetsuzan Yamamoritai, GOLDWIN