Here is a autumn image of California State Highway 101 - as it by-passes The Avenue of the Giants.
Humboldt County, California
A flood of historic proportions hit this region just before Christmas, 1964. The sign here shows the high water level through this region. This point is 47 miles (75 km) upstream from the river's Pacific Ocean discharge near Ferndale, California.
A powerful and well written description of this disastrous event can be read at: http://www.humguide.com/seniornews/issues/0412c.shtml