The Arcata & Mad River Railroad began as the Union Wharf and Plank Walk Company.  It was about two miles of red wood plank and rails.  Some time later iron strapping was added to the rails. The line extended from a wharf built in 1854 or 1855 out into the deeper water of Humboldt Bay and crossed tidewater mud flats connecting it to the new city of Union in Northern California.  This settlement began as the jumping off point for the gold seekers heading inland to the Trinity Mountains.  By February 1855 a horse drawn cart running on wood rails was the first conveyance, thus some historians call it the first operating railroad in California.  In 1860 Union became the city of Arcata and the railroad in  time became the Arcata & Mad River Railroad.   During the the early 1940s to the late 1950 this short line a was one of the busiest and most profitable railroads in the US.  She provided shipping of timber for the building of the US after World War II.  Local residents affectionately called her the "Annie and Mary."  The owners shut down the railroad in the late 1980s after many of the sawmills it served closed down and the line was no longer profitable.

The picture above  shows the remains of the pier built into the northern part of Humboldt Bay near Arcata as seen at low tide.