Autumn in Karuizawa brings forests of larch trees turned golden and woodlands where the trees bear plentiful fruit. As the leaves fall, the forest opens up, and late autumn is also a good season for observing wild animals. Picchio, based in Karuizawa, Nagano Prefecture, offers four nature tours for enjoying the season: "Ko-Asama Trekking" (小浅間山トレッキング), a trek with views of Mt. Asama and a sea of larch trees; "Wild Bird Forest Nature Watching" (野鳥の森ネイチャーウォッチング), which has guides explain the workings of the autumn forest; "Flying Squirrel Watching" (空飛ぶムササビウォッチング), which observes squirrels gliding through the forest at dusk; and "Autumn Forest Walk With a Nature Guide" (ネイチャーガイドと巡る、彩る秋の森さんぽ), an easy outing that can be combined with a visit to Harunire Terrace.
1. "Ko-Asama Trekking" (小浅間山トレッキング), a Fully Private Tour With Scenic Views and Autumn Foliage
A dedicated nature guide accompanies this private tour, which climbs at the pace of each family or group. The route heads for the 1,655 m summit of Mt. Ko-Asama (小浅間山) through larch forests in autumn colors.
A 360-Degree Panorama and the Satisfaction of Reaching the Summit
At the summit, a 360-degree panorama opens up. A sea of golden larch trees spreads out below, and the slopes of Mt. Asama rise directly ahead. Visitors can feel a sense of freedom rarely found in daily life, together with the satisfaction of completing the climb.
A Rare "False Tree Line" at 1,655 m
On central Honshu, the tree line is generally said to lie at an elevation of about 2,500 m. On Mt. Ko-Asama, however, a "false tree line" (偽森林限界, gishinrin-genkai), where tall trees do not grow, can be seen near the 1,655 m summit. It exists because volcanic gravel and rubble produced by eruptions of neighboring Mt. Asama cover the summit area, creating soil in which water and nutrients struggle to accumulate, and because the harsh location is exposed to strong winds.
These conditions create a barren landscape reminiscent of an alpine zone at around 2,500 m. In a climb of only about one hour, visitors can experience up close a distinctive natural environment where alpine plants grow, along with the dynamism of a volcano, which is part of what sets Mt. Ko-Asama apart. The guide's explanations also cover how the mountain formed and how nature works there.
Tea Time at the Summit at Your Own Pace
Because the tour is a private tour limited to one group, taking photos and resting can be done at the group's own pace. Beginner climbers and families can also head for the summit at their own pace with the dedicated guide. Tea time is arranged at the summit, where participants can enjoy the view and spend a relaxed time after reaching the top.
"Ko-Asama Trekking" (小浅間山トレッキング) Overview
- Period: September 1 to November 30, 2026 (the larch trees' yellow foliage can be enjoyed from mid to late October)
- Time: Set according to your request (tour duration: 3 hours to 3 hours 30 minutes)
- Price: ¥38,000 (tax included, per group of up to 6 people)
- Eligibility: Elementary school students and older (beginners and families welcome). Preschool-age children in their final year of kindergarten (年長) may be accepted upon consultation
- Reservation: Required, no later than 7 days before the desired date, through the official website
- Check-in location: Picchio Wild Bird Forest Visitor Center (about 20 minutes by car to the trailhead)
2. Autumn Theme: "Forest of Autumn Colors and Fruits" in "Wild Bird Forest Nature Watching" (野鳥の森ネイチャーウォッチング)
Set in the Karuizawa Wild Bird Forest, which turns red and yellow in autumn, this hands-on tour has a nature guide unravel the "dramas of nature" that are easily overlooked when simply walking. Guides with specialist knowledge explain topics such as the differences in the shapes of tree nuts and fruits and the ways birds get through the winter, introducing the wonders of how the forest works. Participants also learn how to use binoculars and how to find animal tracks, so they can take home ways of observing nature that remain useful after the tour. Immersing all five senses in the forest, from the sound of fallen leaves to the scent of tree nuts, makes for a relaxing time.
"Wild Bird Forest Nature Watching" (野鳥の森ネイチャーウォッチング) Overview
- Period: Year-round (daily)
- Time: 10:00 AM to 12:00 PM (year-round) / 1:30 PM to 3:30 PM (late March to the end of November)
- Price: Adults (junior high school students and older) from ¥2,500 / ages 4 to elementary school students from ¥1,200 (tax included). Prices vary by date
- Eligibility: Anyone (children below elementary school age must be accompanied by a guardian)
- Capacity: 20 people per session
- Reservation: Required, through the official website
- Check-in location: Picchio Wild Bird Forest Visitor Center
3. "Flying Squirrel Watching" (空飛ぶムササビウォッチング) in an Autumn Forest With Clear Views
At dusk, this tour observes the moment wild flying squirrels take off from their nest boxes. After learning about the animals' ecology in a lecture beforehand, participants head into the forest as darkness falls. As autumn deepens and leaves fall, fewer leaves block the view, making it easier to see the squirrels gliding across the evening sky. The clear view of the leaf-fall season is available only at this time of year. Waiting breathlessly for the moment a squirrel leaps from its nest box is an exciting experience. Participants who successfully observe a flying squirrel receive a "Flying Squirrel Watcher Certificate" (ムササビウォッチャー証明書).
"Flying Squirrel Watching" (空飛ぶムササビウォッチング) Overview
- Period: Mid-March to November 30
- Time: Varies with sunset (duration: about 1 hour 30 minutes). Start times change by season, so check the website for details
- Price: Adults (junior high school students and older) from ¥3,400 / ages 4 to elementary school students from ¥2,500 (tax included). Prices vary by date
- Eligibility: Ages 4 and older
- Capacity: 20 people per session
- Reservation: Required, through the official website
- Check-in location: Picchio Wild Bird Forest Visitor Center
4. "Autumn Forest Walk With a Nature Guide" (ネイチャーガイドと巡る、彩る秋の森さんぽ), a Short Outing From Harunire Terrace
The tour is just a short walk from Harunire Terrace, a spot in the Karuizawa Hoshino Area, along a promenade beside a clear stream. It is a short, casual nature tour that can be joined between café time, shopping, or meals at Harunire Terrace, without worrying about clothing or equipment.
With a nature guide, participants take a relaxed walk through the colorful forest next to Harunire Terrace. In the forest, with its pleasant autumn breeze, they can enjoy the sound of fallen leaves underfoot and discover the secrets of colored leaves and autumn tree nuts, so everyone from adults to children can easily experience the charm of nature. Participants can also take home a craft made from fallen leaves. The tour can be fitted in while strolling around Harunire Terrace or during spare time between sightseeing stops.
"Autumn Forest Walk" (秋の森さんぽ) Overview
- Period: Tuesdays, Wednesdays, and Thursdays from September 29 to November 12, 2026 (excluding October 27 to 29)
- Time: 12:30 PM and 2:00 PM, twice a day (about 40 minutes each)
- Price: ¥1,500 (tax included). Free for ages 3 and under
- Eligibility: Anyone
- Reservation: Available through the official website / on-site sign-up on the day
- Check-in location: In front of 川上庵 (Kawakami-an) at Harunire Terrace
