The snow-covered trees of Zao, known as “ICE MONSTER”, are one of the most spectacular natural phenomena of the Japanese winter. Created by a combination of snow, ice, and freezing winds, these enormous formations have made Zao famous around the world.
The snow monsters form when Aomori fir trees, a conifer that grows in Japan’s subalpine zones, become covered with layers of snow and ice. Their appearance changes dramatically between day and night. Under a clear blue sky, they appear dressed in brilliant white, while after dark, illuminated snow monsters seem to emerge from the darkness like enormous figures in a fantastic world.
During winter, visitors can experience the Snow Monster Night Cruising. After the sun sets early over the mountains, visitors travel by ropeway from the area near Zao Onsen to Juhyo Kogen Station and then board a snow vehicle for the Juhyo Fantasy Corridor Tour.
Although temperatures outside can fall well below freezing, the sight of enormous white formations gradually appearing from the darkness creates an extraordinary experience, almost as if you have wandered into another dimension.
Zao Onsen is said to have been established around 110 CE and has historically been known as Takayu or Mogami Takayu. The main street of the hot-spring town, Takayu-dori, has a history stretching back approximately 300 years to the Edo period. Traditional inns and public bathhouses line the street, preserving the atmosphere of an old Japanese hot-spring resort.
Zao Onsen Ski Resort was established in the latter part of the Taisho period (1912–1926) and developed together with the hot-spring town into a mountain resort known both in Japan and internationally.
Zao is not only a winter destination. Throughout the rest of the year, visitors can enjoy the crisp mountain air, lush greenery, alpine plants, and colorful autumn foliage. Hiking, trekking, and relaxation facilities are also available, making Zao a mountain resort that can be enjoyed throughout all four seasons.
The Snow Monster Light-Up can be enjoyed around Jizo Sancho Station, reached by transferring to the upper section of the ropeway from Juhyo Kogen Station.
When the snow monsters are illuminated with colorful lights, the vast panorama of frozen trees takes on an almost dreamlike appearance. The scenery is recognized as part of Japan’s Nightscape Heritage, a designation highlighting outstanding nighttime landscapes.
Some of the largest snow monsters can grow to more than 5 meters tall, and each formation has its own distinctive shape and character. The combination of enormous white trees and colorful illumination creates one of Zao’s most memorable winter landscapes.
Similar snow-covered trees can also be seen in other mountainous areas of Japan, including Mount Hakkoda in Aomori Prefecture and Mount Azuma in Fukushima Prefecture. However, Zao is particularly famous for the scale and accessibility of its snow monster landscape.
Snow monsters are an exceptionally rare natural phenomenon and can only be seen in a limited number of locations. Zao has the special combination of environmental conditions needed to create them.
One important factor is the seasonal winds from Siberia, which carry large amounts of supercooled water droplets and snow toward the mountains. Another is the presence of Aomori fir trees, whose branches provide ideal surfaces for ice and snow to accumulate. Sufficient snowfall is also essential.
When all of these conditions occur together, layer after layer of ice and snow builds up on the trees, producing the spectacular formations known as Zao’s snow monsters.
The Aomori fir trees begin to accumulate ice and snow as clouds of supercooled water droplets carried by the seasonal winds freeze onto their branches.
As winter intensifies, the formations grow rapidly. Ice and snow accumulate especially on the windward side of the trees, producing distinctive shapes known as “ebi no shippo,” or “shrimp tails.”
In February, icing and snowfall are at their most active. The formations can reach their largest size, creating the spectacular landscape for which Zao is famous.
As temperatures rise, the snow monsters begin to melt and become smaller. Rain and warmer conditions can cause the accumulated snow and ice to collapse rapidly.
The appearance of the snow-covered trees also changes depending on altitude. Moving upward from the lower slopes, visitors may encounter rime-covered trees, “ebi no shippo” formations, and full-scale ICE MONSTERS. The boundaries between these stages are not fixed, however, because the formations continually grow and decline throughout the season.
Even at the same elevation, the amount of snow and ice can differ considerably depending on whether a location is directly exposed to the prevailing winds. This is one reason why each part of the Zao snow monster forest has its own distinctive appearance.
Because the formations occur only near the summit during the harshest part of winter, when temperatures can fall to around -15°C, their existence remained largely hidden from the outside world for a long time.
Local people traditionally referred to them as “Yuki no Bo,” or “snow monks.” The phenomenon gradually became known throughout Japan under the name “juhyo,” meaning trees covered in ice and snow, during the Taisho period.
Today, the extraordinary appearance of the formations has become one of the symbols of Zao and one of Japan’s most distinctive winter landscapes.
The snow monsters are magnificent when their white forms stand out against a bright blue winter sky. At night, however, the illuminated formations create a completely different atmosphere.
The ropeway gondola provides an aerial perspective over the vast snow-covered forest. From above, visitors can see how the individual formations spread across the mountain slopes.
Near Jizo Sancho Station, visitors can see the snow monsters from close range. Standing among these enormous formations gives a much stronger sense of their size and unusual shapes.
The Sancho Terrace at Jizo Sancho Station offers a panoramic view of the surrounding snow monster forest. From here, visitors can enjoy a wide, elevated view of the winter landscape.
For those who want to stay warm, Restaurant Sancho provides an indoor viewing opportunity. Visitors can enjoy the snow monster scenery from a warm interior while taking a break from the cold mountain environment.
The most popular way to visit the snow monsters is by taking the Zao Ropeway. Visitors transfer from the Sanroku Line to the Sancho Line and continue to Jizo Sancho Station.
Because the ropeway can be used even by visitors who do not ski or snowboard, it provides an easy way for almost anyone to experience the snow monster landscape.
During the winter season, the Snow Monster Light-Up transforms the frozen forest after dark. The formations are illuminated in a variety of colors, creating an otherworldly scene that looks completely different from the daytime landscape.
Visitors can also take the Night Cruiser, a specially equipped snow vehicle operated in connection with the Zao Ropeway. The vehicle takes visitors into the snow-covered forest for the Juhyo Fantasy Corridor Tour.
The Juhyogen Course at Zao Onsen Ski Resort allows skiers and snowboarders to enjoy the snow monster scenery during the daytime. The experience of moving through the mountain landscape surrounded by enormous frost-covered trees is one of the highlights of winter in Zao.
The snow monster season generally lasts from around late December to late February. The exact timing and size of the formations vary according to weather and snow conditions, so visitors should check the latest operating information when making reservations for ropeway rides, tours, or other activities.
Zao Onsen Ski Resort offers long downhill courses surrounded by the famous snow monsters, allowing visitors to combine winter sports with spectacular scenery.
The Night Cruiser snow vehicle tour provides a special way to experience the illuminated snow monster forest after dark.
Zao Kaiun Meguri is a route for visiting places associated with good fortune and spiritual energy around the Zao area. It provides another way to experience the cultural side of the mountain alongside its natural scenery.
Zao also features a location recognized as a “Lover’s Sanctuary,” a designation associated with romantic destinations and proposals. It offers couples a memorable setting amid the mountain scenery.
After spending time in the snow-covered mountains, visitors can warm up in the area’s natural hot springs. Zao Onsen is famous for its traditional open-air and public bathing facilities, making a hot-spring bath a relaxing way to finish a winter excursion.
The Zao Snow Monsters are not simply trees covered with snow. They are the result of a remarkable combination of geography, climate, vegetation, wind, ice, and snowfall that occurs only under very specific conditions.
Their appearance changes from month to month and even from hour to hour. Bright sunlight reveals their pure white forms, while nighttime illumination transforms them into mysterious figures rising from the darkness.
For travelers visiting Yamagata in winter, experiencing the ICE MONSTER landscape of Zao offers an opportunity to witness one of Japan’s most unusual and spectacular natural phenomena.