The Mad River north of Arcata has been tamed for the summer. A large, long, water tight bag has been stretched across the entire river, about 200 yards from U.S. Highway 101. (notice I didn't say the 101). The river is closed to anglers, kayaks and boats of any kind during construction of the first of two new bridges to replace the two old and aging ones. The oldest of the two will be left in place for bicycles and pedestrians.
The rear of a sign that alerts boaters of the closure is what I assume I photographed. It may also say, "End Construction". I have noticed they have to put those signs all over the place to let the construction workers know where to stop.
The water filled dam does make for a small lake of sorts.