Oirase Stream (奥入瀬渓流, Oirase Keiryū) is a picturesque mountain stream in Aomori Prefecture that is one of Japan’s most famous and popular autumn colors destinations. The stream flows along the floor of the Oirase Gorge, winding among trees which, while a lush green in spring and summer, turn brilliant shades of red, yellow and orange from late October through early November. Over a dozen waterfalls cascade down into the stream all along its length from the walls of the gorge.
Oirase Stream is the only outlet draining Lake Towada. It starts at Nenokuchi where there is a bus stop and a boat pier with connections to nearby Yasumiya Town. An easy-to-walk hiking trail leads along the most scenic, upper passage of the stream between Nenokuchi and Ishigedo, with many bridges, waterfalls and bus stops along the way. The trail is about 9 kilometers long and takes about 2.5 hours to walk one way.