Oirase Gorge

Oirase Gorge is a 14-kilometer scenic stream valley in Aomori Prefecture, stretching from Lake Towada to the Yakeyama lava flow in northern Honshu. The gorge was formed by volcanic activity from Mount Towada approximately 13,000 years ago, with the Oirase Stream carving through dense virgin forest over millennia. The area gained protection as part of Towada-Hachimantai National Park in 1936, preserving one of Japan's most pristine temperate forest ecosystems.

The gorge holds significant ecological value as home to over 300 species of moss blanketing rocks and trees throughout the valley, creating an otherworldly landscape particularly striking after rainfall. The forest canopy consists primarily of Japanese beech, oak, and maple trees, while the stream itself features numerous waterfalls including the 20-meter Choshi Otaki, the gorge's largest cascade. This untouched natural environment represents one of the few remaining old-growth forests in Japan's northern regions.

Visitors typically explore the gorge via the Oirase Stream Trail, a flat walking path that follows the entire length of the stream. The trail allows close access to cascades, rapids, and moss-covered rock formations, with viewing platforms positioned at major waterfalls including Kumoi no Taki and Shirataki. Autumn draws the largest crowds when maple leaves create vivid red and gold corridors, typically peaking in late October. Spring through early summer offers lush green scenery and seasonal wildflowers, while winter transforms accessible sections into a snow-covered landscape, though portions of the trail close due to heavy snowfall.

The gorge is accessible by bus from Aomori City (approximately 2 hours) or Hachinohe Station (90 minutes), with services operated by JR Bus Tohoku connecting to Yakeyama trailhead. Local shuttle buses run along the gorge during peak seasons, allowing visitors to walk one section and return by bus. No admission fee is charged for accessing the gorge or walking paths. The nearest accommodations cluster around Lake Towada at the southern terminus and at Yakeyama on the northern end, with several traditional ryokan and hotels providing access points to different trail sections.