The Mountain Quarries Railroad Bridge, also known as "No Hands Bridge," was completed on March 23, 1912. At the time of its construction, it was one of the largest reinforced concrete railroad bridges in the United States and the largest such bridge owned by private capitol. Since 1912, it has withstood the fluctuations of the American River and remained on its footings when the Hell Hole dam failed in December 1964, destroying two more modern bridges upstream. It also survived the "Valentines Day Flood" of 1986, which submerged the bridge before destroying a 250 foot earth filled coffer dam two miles downstream. The old concrete bridge stands today as an icon in the American River Canyon and a monument to early engineering innovations and the men who built it.