A Crystal-Clear Lake in an Enchanted Forest
The clear waters of Lake Shirakoma blend beautifully with the surrounding primeval forest. Hundreds of years-old trees and thick carpets of moss create a mysterious landscape where the forest seems to extend directly into the water.
Autumn is one of the most spectacular seasons to visit. Red, orange, and golden foliage surrounds the lake and is reflected on its calm surface, creating scenery that resembles a painting. A walking trail follows the lakeshore, allowing visitors to enjoy the forest and lake at a leisurely pace.
Because some sections of the trail can become slippery with moss and moisture, comfortable walking shoes or hiking shoes are recommended.
How Lake Shirakoma Was Formed
Lake Shirakoma is a dammed lake formed when an eruption of Mount Shirakoma blocked the flow of the Oishikawa River. The lake covers approximately 0.11 square kilometers, with a circumference of about 1.35 kilometers.
Its maximum depth is approximately 8.6 meters, while water transparency reaches around 5.8 meters. Despite its relatively small size, its high-altitude setting and pristine natural environment give the lake a distinctive character.
By late November, the lake usually freezes completely. The area is also known for being one of the earliest places on the main island of Honshu where skating on a frozen lake has traditionally been possible.
The Ancient “Moss Forest”
The forest surrounding Lake Shirakoma is home to primeval stands of Tsuga diversifolia, spruce, and Maries’ fir, including trees that are several hundred years old. Beneath them lies a thick carpet of moss that covers the forest floor like a green blanket.
This remarkable ecosystem is known as the “Moss Forest” and has been selected by the Bryological Society of Japan as one of Japan’s precious moss forests. The area also supports alpine plants and deciduous trees such as Japanese enkianthus, allowing visitors to experience a rich variety of high-altitude vegetation.
Access to the Lake
Lake Shirakoma can be reached relatively easily from the parking areas along National Route 299, also known as the Romantic Road. From the parking area, the lake is approximately a 15-minute walk away.
There is a paid parking lot managed by the local forestry cooperative, as well as the free Mugikusa Public Parking Area near Mugikusa Hutte. During the autumn foliage season, the area can become particularly busy, and traffic congestion may occur on the mountain road. Allowing plenty of extra time is recommended when visiting during peak season.
Seasonal Bus Services
Seasonal bus services are available from the Saku area. Chikuma Bus operates services toward Mugikusa Pass from JR Sakudaira Station, via Nakagomi and Yachiho stations on the JR Koumi Line.
From the Chino area, Suwa Bus also operates seasonal services toward Mugikusa Pass, with routes that pass by the Lake Shirakoma area. Because these services operate seasonally, travelers should check the latest timetable before planning their journey.
Mountain Huts Beside the Lake
Seitaiso
Seitaiso stands on the northern shore of Lake Shirakoma. The mountain lodge includes a shop and campground and serves as a useful base for hikers exploring the surrounding mountains.
Shirakomaso
Shirakomaso is located on the western shore of the lake. Meals and accommodation are available, allowing visitors to stay close to the water and experience the quiet atmosphere of the mountain after the day-trippers have left.
Hiking Around Lake Shirakoma
Lake Shirakoma is also an important destination on hiking routes through the Northern Yatsugatake Mountains. One of the most rewarding viewpoints is Takamiishi, from where hikers can look down over the lake surrounded by the deep green forest.
Continuing toward Mount Nyū leads to the Shirakoma Marsh, where seasonal alpine plants such as cotton grass bloom. The landscape changes throughout the year, making the area attractive not only for serious hikers but also for visitors who enjoy quiet nature walks.
The Legend Behind the Name “Shirakoma”
Lake Shirakoma is also associated with a traditional local legend. Long ago, a young man and woman fell in love, but the woman’s father opposed their relationship and drove the man deep into the mountains.
The woman followed him into the mountains but became lost. At that moment, a white horse appeared and guided her to the lake, telling her that the man was in the water. According to the legend, the woman disappeared into the lake together with the white horse and never returned.
The white horse was called “Shirakoma,” meaning “white colt”, and this mysterious story is said to be the origin of the lake’s name. The legend adds another layer of mystery to an already atmospheric landscape.
Different Ways of Writing the Lake’s Name
Visitors may notice that the lake’s name appears in several forms, including Shirakoma-ike, Shirakoma no Ike, and Shirakoma-no-Ike. The Geospatial Information Authority of Japan uses “Shirakoma-ike” on its maps, while books, tourism brochures, and signs may use different forms.
These variations all refer to the same lake and reflect differences in regional usage and historical sources.
A Mountain Lake of Moss, Forests, and Legends
Lake Shirakoma is a unique high-altitude destination where a pristine mountain lake, ancient forest, moss-covered ground, alpine vegetation, and local legend come together. Its elevation of 2,115 meters gives the landscape a distinctive character, while the surrounding forest creates a sense of seclusion rarely found so close to a road-accessible destination.
Autumn foliage is particularly spectacular, but every season offers a different experience, from summer greenery and alpine flowers to the quiet beauty of a frozen winter lake. With walking trails, mountain huts, viewpoints, and hiking routes into the Northern Yatsugatake Mountains, Lake Shirakoma is an unforgettable destination for anyone seeking the mysterious beauty of Japan’s high mountains.