The most prevalent species of the extreme southern portion of the watershed is the coastal redwood, one of the tallest types of trees on Earth. The world's northernmost redwood grove is located near the south bank of the Chetco at RM 15 (RK 24), about north of the California border. Trees here are around 300 to 800 years old, in diameter, and some exceed tall. The redwoods were heavily logged in the early 20th century. Prior to logging, the massive trees created their own microclimate by capturing moisture from fog, and also by the immense amount of shade they produced. The redwoods region is less mountainous than the rest of the watershed, and meandering streams are much more common.