Matsukawa Onsen (松川温泉)

Introduction: The Milky-White Sanctuary of the Geothermal Heartland

Deep within the primeval forests of the Towada-Hachimantai National Park, at an elevation of 850 meters along the rushing Matsu River, lies Matsukawa Onsen (松川温泉). Established over 280 years ago, this hot spring is a legendary “Hitou” (hidden hot spring) that represents the atmospheric peak of the Tohoku wilderness. It is a place defined by its striking milky-white sulfur waters, its traditional wooden architecture, and its proximity to Japan’s first geothermal power plant. For the international traveler, Matsukawa Onsen offers a profound sensory journey: soaking in opaque “Medicine Waters” while being surrounded by emerald-green beech trees in summer or meter-high snow walls in winter. It is a sanctuary of absolute silence, where the only sounds are the rustle of the forest and the steam rising from the volcanic earth. Whether you are a dedicated hiker aiming for the Hachimantai summits or a wellness seeker looking for a digital detox, Matsukawa provides a warm, mysterious, and deeply restorative embrace.

Key Information Table

The Healing Waters: The “Medicine” of the High Caldera

The water at Matsukawa Onsen is geologically intense, drawing its power from the deep volcanic veins of the Hachimantai range. It is a powerful Simple Sulfur Spring.
The Visuals: The water emerges crystal clear at high temperatures but reacts instantly with the oxygen in the mountain air to turn a striking, opaque milky-white or pale turquoise.
The Sensation: This is a “Medicine Bath” (Kusuri-yu) in its most raw form. The sulfur content acts as a powerful antiseptic for the skin and promotes intense peripheral blood circulation, warming the body from the core outward. The three lodges each have their own source, but all share a commitment to 100% natural flow (Gensen Kakenagashi). The outdoor Rotenburo baths here are legendary; soaking in the “Milky Pool” while looking at the snow-covered Japanese Oak trees is one of the most spiritual thermal experiences in Northern Japan.

Top Recommended Stays: The Three Guardians of Matsukawa

• Kyoun-so (峡雲荘): A traditional wooden inn that blends seamlessly with the forest. It is famous for its massive mixed-gender outdoor bath (Konyoku) and its cuisine featuring local mountain vegetables and Iwate wagyu. It is the premier choice for international hikers.
• Matsukawa-so (松川荘): Located slightly upstream, this lodge features a beautiful Rotenburo right by the riverbank. It offers a very authentic, rustic atmosphere and is highly regarded for its “Toji” (healing) packages.
• Suigen-so: A smaller, more intimate guesthouse that focuses on quietude and mineral purity. It is a favorite for solo travelers and those seeking a “home-away-from-home” feel.
• Hachimantai Mountain Hotel (Nearby): For those who prefer modern resort amenities, staying at this facility in Higashi-Hachimantai and visiting Matsukawa as a day-trip is a popular strategy.

Must-Visit Neighborhood Spots: Power and Forests

Matsukawa Geothermal Power Plant: The first of its kind in Japan. The sight of its cooling towers billowing steam against the mountains is an iconic industrial-landscape photograph.
Mori-no-Ohashi Bridge: A stunning viewpoint near the onsen area, offering panoramic views of the Matsukawa gorge, especially breathtaking during the autumn foliage peak in mid-October.
Hachimantai Aspite Line: A short drive away, Japan’s most scenic mountain road, famous for its “Snow Corridor” (walls of snow) in spring.

Local Gastronomy: The Bounty of the “Mountain-River”

Food in Matsukawa is honest, rustic, and deeply tied to the land.
Horo-ho-ro-cho (Guinea Fowl): A local specialty of Hachimantai. The meat is lean, flavorful, and often served as sashimi or grilled.
Iwate Wagyu: Award-winning beef known for its sweetness and marbling.
Vegetarian/Vegan Survival:
For Vegans: This area is a leader in Mountain Vegetables (Sansai). At the ryokans, request the “Sansai Feast”—specify “Katsuo-dashi nuki” (No fish dashi). The local “Hachimantai Tofu” is famous for its dense texture and rich soy flavor. We recommend buying the local “Hachimantai Honey” as a savory-sweet souvenir (for those who consume honey).

Cultural & Historical Context

The name “Matsukawa” refers to the “Pine River” that flows through the valley. Historically, the area was a vital territory for mountain priests and early pioneers. The onsen gained national attention in the mid-20th century as a symbol of Hokkaido/Tohoku’s “Hitou” spirit—a place that resists modern commercialization to protect the mineral and spiritual purity of the forest. Today, it remains a model for sustainable thermal tourism, where the energy of the earth (geothermal) and the healing of the people are inextricably linked.

Practical Travel Tips for International Visitors

• Mixed Bathing (Konyoku): Kyoun-so and Matsukawa-so feature mixed-gender outdoor baths. While traditional, wearing a bathing wrap or towel is permitted for women to ensure comfort. There are also dedicated hours for women only.
• Tattoo Policy: As a traditional and quiet “Hitou,” Matsukawa is generally very tolerant of tattoos. The owners focus on the healing quality of the water and the peace of the mountain. Full ink pieces are rarely an issue here if the guest is respectful.
• Connectivity: Mobile signal can be weak. Wi-Fi is generally available in the ryokan lobbies but not always in the guest rooms. Prepare for an “analog” retreat.
• Cash Only: While the major lodges may accept credit cards, the day-trip bath entry and the local bus are strictly cash-only (JPY). Withdraw sufficient cash in Morioka before heading up.

2025-2026 Latest Updates

In 2025, Matsukawa Onsen launched the “Geothermal & Wellness Trail,” providing digital maps and historical guides to the power plant and the forest baths. For the 2026 winter season, the bus service from Morioka is being upgraded with more English-speaking drivers and multilingual automated announcements.

Safety & Manners

In the sulfur-rich onsen, remove all silver jewelry as it will turn black instantly. Always rinse your body thoroughly before entering the tub. Because the water is opaque, walk carefully to find the submerged steps. Be “Bear Aware”—carry a bear bell if you are hiking the Hachimantai trails alone. Finally, respect the quiet; Matsukawa is a place for healing, so keep conversations in the communal baths to a respectful whisper.