Complete Guide to Shirakomano Ike (Nagano Prefecture) | Thorough Explanation of Japan’s Highest Natural Lake and the Charm of the Moss Forest
What is Shirakomano Ike | A Mystical Natural Lake at Japan’s Highest Elevation
Shirakomano Ike (White Pony Pond) is a natural lake located at 2,115 meters elevation on the border between Sakuho Town and Koumi Town in Minami-Saku District, Nagano Prefecture. It boasts the largest size among lakes at elevations above 2,100 meters in Japan, and is known for its mystical landscape cradled by the vast primordial forest of the Northern Japanese Alps (Kita-Yatsugatake).
The circumference of the pond is approximately 1.35 kilometers, with a maximum depth of about 8.6 meters. Despite easy access just a 15-minute walk from a parking lot along National Route 299 (nicknamed Märchen Road), stepping into the forest reveals a completely different world—a special place.
Geographic Characteristics of Shirakomano Ike
Shirakomano Ike is located in one corner of the Yachio Kogen Plateau, on the eastern slope of the Northern Japanese Alps. This region was formed by volcanic activity, and Shirakomano Ike itself is thought to have been created as a dammed lake accompanying volcanic activity.
At 2,115 meters elevation, the pond is located at the entrance to the alpine zone, in what is classified as the subalpine zone. At this elevation, summers remain cool, and in winter the pond completely freezes with ice thickness sometimes exceeding 60 centimeters. The surrounding annual average temperature is approximately 3°C, and these harsh climatic conditions nurture a unique ecosystem.
Geologically, volcanic ash and organic matter have accumulated at the bottom of the pond, reaching several meters in thickness. The water source comes primarily from groundwater seeping from the surrounding primordial forest and rainwater, with no outflowing stream from the pond. This results in high water transparency, and on clear days, the surrounding primordial forest is mirrored on the pond’s surface in a beautiful sight.
The Primordial Forest and Moss Forest Surrounding Shirakomano Ike
The greatest charm of Shirakomano Ike is the existence of the primordial forest and moss forest that encircles it. This area has been selected as “Japan’s Precious Moss Forest” by the Japanese Bryological Society, and is said to be home to approximately 485 to over 500 moss species.
Composition of the Primordial Forest
The primordial forest surrounding Shirakomano Ike is composed mainly of coniferous trees such as Momi (Sakhalin Fir), Tsuga (Hemlock), and Touhi (Spruce). Many of these trees reach ages of several hundred years, and the “forest cycle” continues today, where fallen and decaying wood becomes the seedbed for new life.
The forest floor is covered entirely by moss, presenting a landscape like a green carpet spread throughout. This moss layer reaches depths of several tens of centimeters in thick areas, playing the role of absorbing and storing water like a sponge. This abundant moisture serves as the foundation supporting the diverse moss species.
Diversity of the Moss Forest
The moss species confirmed in the area surrounding Shirakomano Ike boast some of the most diverse moss diversity within Japan. Representative species include Hinoki Goke (Leucobryum neilgherrense), Sugi Goke (Hypnum cupressiforme), Mizu Goke (Sphagnum), and Sippo Goke, each preferring subtly different environmental conditions, resulting in different moss communities forming even within just a few meters distance.
Although moss is a photosynthesizing plant, it lacks roots and absorbs moisture directly through leaves and stems. Therefore, it prefers humid environments, and the foggy and wet climate around Shirakomano Ike provides ideal conditions for moss growth.
In particular, different moss species grow in layers on fallen wood, rock surfaces, and tree trunks, creating beauty reminiscent of a natural art gallery. Moss wet with morning dew or fog displays particularly vivid green colors, creating a fantastical atmosphere.
Precautions When Walking in the Moss Forest
The moss forest surrounding Shirakomano Ike is an extremely valuable natural environment. Since moss takes many years to recover once trampled, it is important not to stray from the walking paths. Additionally, collecting moss is strictly prohibited.
When taking photographs, avoid sitting directly on moss or setting up tripods. A “looking and photographing only” attitude is required to preserve this beautiful moss forest for future generations.
Access Methods to Shirakomano Ike
Access to Shirakomano Ike is mainly convenient by car, though public transportation options are also available.
Access by Car
From the Tokyo area:
- Via Suwa IC on the Chuo Expressway, then National Route 152, National Route 299 (Märchen Road): approximately 50 km, about 1 hour 20 minutes
- Via Saku IC on the Chuo Expressway, then National Route 141, National Route 299: approximately 40 km, about 1 hour
From the Nagoya area:
- Via Suwa IC on the Chuo Expressway, then National Route 152, National Route 299: approximately 50 km, about 1 hour 20 minutes
National Route 299 is a scenic road affectionately known as “Märchen Road,” running from Shirakaba Lake over Mugikusa Pass toward the Saku area. The parking lot for Shirakomano Ike is located along this National Route 299 near Mugikusa Pass.
Parking Information
There are multiple parking lots for Shirakomano Ike:
Shirakomano Ike Entrance Parking Lot (Fee-charging):
- Capacity: approximately 200 vehicles
- Fee: 600 yen for standard vehicles, 300 yen for motorcycles (may vary by season)
- Operating period: Late April to early November (depending on snow conditions)
- Approximately 15-minute walk from parking lot to pond
During fall foliage season (late September to early October) and summer weekends, parking lots often reach capacity from early morning, so arrival by 7:00 AM is recommended. A live camera is installed at the parking lot, and a website allows advance confirmation of congestion status.
Access by Public Transportation
By JR:
- From Chino Station or Sakudaira Station on the JR Chuo Main Line, via bus or taxi
- Seasonal buses may depart from Chino Station (confirmation required in advance)
- By taxi: approximately 1 hour from Chino Station, approximately 50 minutes from Sakudaira Station
Public transportation access is limited, so rental car use is also worth considering.
Walking Path to Shirakomano Ike
From the parking lot to Shirakomano Ike, a maintained walking path continues. The distance is approximately 500 meters with almost no elevation change, but due to many tree roots and stones, hiking shoes or sneakers that are easy to walk in are essential.
The moss forest spreads on both sides of the walking path, and the atmosphere of the primordial forest can be experienced even in this short distance. The journey takes approximately 15 to 20 minutes one way, but it is recommended to walk slowly while enjoying moss observation and photography.
Hiking Courses Around Shirakomano Ike
Around Shirakomano Ike, a walking path of approximately 40 minutes circumference is maintained, allowing visitors to enjoy the scenery from various angles while going around the pond.
Pond Circumnavigation Course (Duration: approximately 40 minutes)
This course goes around the pond’s circumference either clockwise or counterclockwise. Along the way, there are two mountain huts where visitors can rest, eat, and stay: “Seikokusou” on the south shore and “Shirakomasou” on the north shore.
While circumnavigating the pond, various perspectives of the pond and primordial forest scenery can be enjoyed. Especially at dawn, the water surface is calm like a mirror, and the inverted image of the primordial forest appears mystical. Additionally, the way light strikes changes with season and time of day, revealing different characteristics.
Hiking to Takami Stone (Duration: approximately 30 minutes one way)
A popular hiking route from Shirakomano Ike to Takami Stone (elevation 2,225 meters) also exists. Takami Stone is a scenic spot with massive rocks stacked atop one another, and from the summit spreads a spectacular vista overlooking the entire Shirakomano Ike.
The hiking path is maintained, but due to rocky areas, light mountaineering equipment is necessary. “Takamishi Hut” is located at Takami Stone’s summit, where visitors can enjoy the hut’s famous fried bread.
Hiking to Niu (Duration: approximately 1 hour 30 minutes one way)
Hiking from Shirakomano Ike to “Niu” (elevation 2,352 meters) is also a popular course. “Niu” is a distinctive rock peak offering 360-degree views. On clear days, views extend to the Northern Alps, Southern Alps, Central Alps, and even Mount Fuji.
This is an intermediate-level course with rock passages that beginners can also attempt. Allow approximately 3 to 4 hours for a round trip.
The Charm of Shirakomano Ike Across the Four Seasons
Shirakomano Ike displays different characteristics in each season, offering entirely different experiences depending on when you visit.
Spring (late May to June): Season of Fresh Green Leaves and Snowmelt
Due to its high elevation, spring at Shirakomano Ike arrives from late May through June. During this period, snowmelt water raises the pond water level, and surrounding trees are enveloped in fresh green foliage. Moss recovers its vivid green color, and the forest displays life and vitality.
From late May through early June, some snow may remain, and the contrast between fresh foliage and snow is beautiful. However, snow may remain on walking paths, so advance information confirmation is necessary.
Summer (July to August): Oasis for Cool Refuge and Forest Bathing
Summer at Shirakomano Ike is ideal as a cool refuge. Due to its location above 2,100 meters elevation, even in midsummer temperatures hover around 20°C, providing cool and comfortable conditions.
During this season, moss is most vibrant, and fog frequently appears, creating a fantastical atmosphere. The forest shrouded in early morning fog is particularly mystical and popular among photography enthusiasts.
While many families visit during summer vacation, early mornings and weekdays allow relatively quiet enjoyment of nature.
Autumn (late September to early October): Spectacular Autumn Foliage
The autumn foliage season draws the most tourists to Shirakomano Ike. Typically from late September through early October, species such as Dake Birch, Mountain Ash, and Enkianthus blaze in vivid colors, and the pond’s surroundings become enveloped in a brocade of red, yellow, and orange hues.
The contrast between evergreen deep green and autumn colors, along with inverted autumn foliage reflected in the pond’s water surface, is breathtakingly beautiful. Especially on clear days at dawn and dusk, the angle of light is beautiful, making it the optimal shooting time.
However, parking lots fill from early morning during this season, so arrival by 6:00 to 7:00 AM is recommended, or weekday visits are suggested. Weekends may cause traffic congestion on National Route 299.
Winter (late November to April): Silent Snowy Landscape
From late November, the Shirakomano Ike area becomes snow-covered, and the Mugikusa Pass section of National Route 299 closes for winter. Consequently, winter access to Shirakomano Ike is extremely limited, requiring approach via snowshoes or cross-country skis.
The pond completely freezes with snow accumulating on top. Ice thickness exceeds 60 centimeters, allowing walking on the frozen pond (though safety confirmation is essential).
Winter at Shirakomano Ike is for advanced visitors, but the snowy primordial forest enveloped in silence offers a special experience unavailable in other seasons.
The Origin of Shirakomano Ike’s Name and Legends
The beautiful name “Shirakomano Ike” has several explanations for its origin.
The most famous legend tells of a white horse (koma) appearing at the pond’s edge long ago. The white horse had a divine appearance, and people believed it to be a messenger of the gods, eventually naming the pond “Shirakomano Ike.”
Another theory suggests the name came from the pond’s water surface appearing white and shining. Indeed, when struck by morning or evening sunlight, the pond’s water surface gleams in silver, creating a mystical sight.
Yet another explanation proposes that the appearance of the frozen, snow-covered pond in winter resembled a white horse.
According to local lore, the pond is inhabited by a large master fish. Indeed, the pond is home to fish such as Japanese char, though fishing is prohibited.
Facilities and Accommodations Around Shirakomano Ike
Lodging at Mountain Huts
Two mountain huts around Shirakomano Ike offer lodging and meals.
Shirakomasou:
A mountain hut located on the pond’s north shore offering lodging, meals, and tea service. Lodging is by reservation and offers options from basic rooms to meals included. The hut’s front offers beautiful pond views, and the sunset scenery in particular is exceptional.
Seikokusou:
A mountain hut located on the pond’s south shore also offering lodging and meals. As its name suggests, it is surrounded by beautiful moss forest.
Both mountain huts operate from late April to early November, closing in winter. Reservations are difficult during fall foliage season, so early booking is recommended.
Day-use
Both mountain huts allow day-use, providing light meals and beverages. They are ideal for rest after circumnavigating the pond.
Surrounding Accommodations
When overnight stays at Shirakomano Ike are difficult, numerous accommodations exist in surrounding Yachio Kogen and Chino and Saku cities. Hotels, ryokan inns, and pensions are scattered within 30 minutes to 1 hour by car.
Clothing and Belongings for Visiting Shirakomano Ike
Proper preparation is necessary when visiting Shirakomano Ike, located at over 2,100 meters elevation.
Clothing
- Spring and Autumn: Temperatures are over 10°C lower than lowlands, making fleece or down jackets essential. Prepare layered clothing.
- Summer: Daytime is cool and comfortable, but mornings and evenings are cool, so bring a long-sleeved jacket.
- Shoes: While walking paths are maintained, many tree roots and stones exist, requiring comfortable hiking shoes or sneakers. Sandals and heels are inappropriate.
- Rain Gear: Mountain weather changes quickly, making rain wear essential.
Belongings
- Drinking water (purchasable at mountain huts but bring your own as standard)
- Snacks (chocolate, nuts, etc.)
- Sunscreen (high elevation intensifies UV rays)
- Hat
- Camera (to record beautiful scenery)
- Map or guidebook
- Mobile phone (coverage may be limited in some areas)
- Garbage bag (always take trash with you)
Best Season for Shirakomano Ike Tourism and Avoiding Crowds
Best Season
Autumn Foliage Season (late September to early October): Most popular, offering beautiful foliage. However, crowds are also at maximum.
Fresh Green Season (June): Vivid green and beautiful moss can be enjoyed quietly. Relatively uncrowded.
Summer (July to August): Ideal for cool refuge and forest bathing. Weekends are crowded, but weekdays are peaceful.
Tips for Avoiding Crowds
- Early Morning Visits: Especially during foliage season, aim for 6:00 to 7:00 AM arrival. Early mornings also offer good lighting and quiet pond enjoyment.
- Weekday Visits: Weekday visits are recommended if possible. The difference in weekend crowding is significant.
- Slight Foliage Season Adjustment: Targeting slightly before or after the peak (early October) results in relative quiet.
- Live Camera Confirmation: Parking lot live cameras allow advance congestion confirmation.
Natural Conservation Activities Around Shirakomano Ike
Shirakomano Ike and its surrounding primordial forest and moss forest represent extremely valuable natural environments. Various conservation activities are conducted to protect this environment.
Environmental Conservation Efforts
- Walking Path Maintenance: Wooden walkways and paths are maintained so visitors don’t trample moss.
- Parking Fee System: Charging for parking secures funds for environmental conservation.
- Awareness Activities: Signs and pamphlets encourage moss protection and collection prohibition.
- Regular Environmental Surveys: Moss species and growth condition surveys are conducted periodically.
Etiquette Expected of Visitors
- Don’t Stray from Walking Paths: Moss is extremely delicate, taking years to recover once trampled.
- No Plant Collection: Moss, flower, and fruit collection is strictly prohibited.
- Carry Out All Trash: Always take all garbage with you.
- Keep Quiet: Avoid loud voices and respect nature’s silence.
- Pet Accompaniment: If bringing pets, always use a leash and remove feces.
Other Attractions Around Shirakomano Ike
When visiting Shirakomano Ike, nearby tourist spots can also be enjoyed.
Mugikusa Pass
Located approximately 10 minutes by car from Shirakomano Ike, Mugikusa Pass (elevation 2,127 meters) is Japan’s second-highest national route pass. The pass offers views of Northern Japanese Alps mountains and serves as a mountain climbing starting point.
Yachio Kogen Plateau
A highland area spreading to the east of Shirakomano Ike featuring birch forests and highland flowers. Ski resorts and golf courses also exist, providing year-round enjoyment.
Tateshina Kogen and Shirakaba Lake
Traveling west from Shirakomano Ike along National Route 299 leads to Tateshina Kogen and Shirakaba Lake. Resort facilities are well-developed and the area is popular with families.
Northern Japanese Alps Ropeway
A ropeway in the Tateshina area connects 1,771 meters to 2,237 meters elevation in approximately 7 minutes. The mountain top offers views of the Northern Alps and Mount Fuji.
Precautions Regarding Access to Shirakomano Ike
Winter Closure
The Mugikusa Pass section of National Route 299 closes for winter typically from late November through late April. During the closure period, access to Shirakomano Ike is extremely difficult.
Weather-related Closures
Even in summer, heavy rain or typhoon effects may cause National Route 299 closures. Confirm road conditions before visiting.
Mobile Phone Coverage
Mobile phone signal is weak or nonexistent around Shirakomano Ike. Inform family and friends of your destination in advance for emergencies.
High Altitude Sickness Precautions
The high elevation above 2,100 meters may cause mild altitude sickness symptoms (headache, dizziness, shortness of breath) in some people. Avoid overexertion and rest if symptoms appear.
Photography Points and Tips for Shirakomano Ike
Shirakomano Ike is also popular among photography enthusiasts. Here are points for capturing beautiful photographs.
Best Photography Times
- Early Morning (around sunrise): The water surface is calmest, allowing mirror-like reflection photography. Days with morning fog are particularly fantastical.
- Evening (before sunset): Primordial forest illuminated by western sun is beautiful, creating warm-toned photographs.
Recommended Photography Points
- North Shore of Pond (near Shirakomasou): Captures the entire pond and forest broadly.
- East Shore of Pond: Captures sunrise-lit pond and forest.
- Moss Forest Walking Paths: Macro lens reveals moss details with a microscopic world opening.
- Takami Stone Summit: Overhead photographs of the entire pond are possible.
Photography Tips
- Tripod Use: Useful in low-light early morning or evening conditions, but be mindful of other visitors on walking paths.
- Polarizing Filter: Controls water surface reflection and brings out more vivid colors.
- Long Exposure: ND filters enable long exposure for smoothly rendered water surfaces.
- Moss Photography: Early morning with water droplets is best for macro moss photography.
Conclusion: Fully Enjoying Shirakomano Ike’s Charm
Shirakomano Ike, as Japan’s largest natural lake above 2,100 meters elevation, offers a mystical world woven by the primordial forest of the Northern Japanese Alps and over 500 moss species. Despite convenient access just a 15-minute walk from a parking lot along National Route 299, stepping into the forest reveals a completely different world—a special place.
Shirakomano Ike displays different characteristics with each season, offering fresh spring foliage, cool summers, and spectacular autumn colors. Especially the fall foliage season’s beauty is exceptional, continuing to captivate many people.
When visiting, it is important to wear appropriate clothing and prepare properly, respecting nature conservation etiquette. Following basic rules such as not straying from paths, not trampling moss, and carrying out all trash allows this valuable natural environment to be preserved for the future.
Shirakomano Ike and its surrounding moss forest represent a natural treasure of which Japan can be proud. Walking through the primordial forest enveloped in silence and standing at the mystical pond’s edge allows urban bustle to be forgotten and a sense of unity with nature to be felt. When visiting Nagano Prefecture, be sure to visit this special place.
