The valley of the Second River marks the northern limit of Branch Brook Park. Unlike the meandering Branch Brook in the Northern Division, the Second River is a swift flowing tributary of the Passaic River. Its cut through the native sandstone can be seen in the ravine-like walls on the southern side of the roadway. The river was tamed when this part of the park was laid out in the 1920’s by confining it to a concrete-walled channel. Unfortunately, this has had negative consequences for fish and other wildlife that relied on the river’s natural banks.