When gold was discovered in California in 1849 , Dr. William Knight rediscovered a place which he and John C. Fremont had previously found to be a favorable river crossing , and established a ferry boat there . Soon , the ferry boat prospered and Knight and Captain Vantine built a hotel and trading post near the crossing . On November 9 , 1849 , Knight was killed by a gunfight on the town 's main street ; he was buried in an unmarked grave . Knight 's family believed Dr. Knight was stabbed to death in his bed and was buried near the gate in the yard of John Dent 's house , which was Dr. Knight 's place at the time . The Dents immediately took possession of Bill Knight 's property at Knight 's Ferry following the murder . Knights Ferry was also the county seat in 1862 , as it replaced La Grange . It was soon succeeded by the new , prosperous railroad boomtown of Modesto in 1871 . After Knight 's death , Vantine operated the ferry alone until he formed another collaboration with John and Lewis Dent , brothers to President Ulysses S. Grant ’s wife , Julia Grant . In 1852 , Vantine sold his properties in the area to the Dents and moved elsewhere . A new townsite under the name of " '' ' Dentville ' '' " was laid out by John Dent . The inhabitants continued to call the town " Knights Ferry " and " '' ' Knights Crossing ' '' " . In 1852 , a toll bridge replaced the ferry . It was destroyed by the Great Flood of 1862 . The new covered bridge was built at a higher level than the previous one , and it still stands today . The bridge was used for car traffic until it was closed to prevent damage in 1985 . In addition to being the longest covered bridge west of the Mississippi River , the bridge is one of the nation 's finest examples of a Howe truss covered bridge . It was designated a National Historic Landmark in 2012
Great Flood of 1862
Great Flood of 1862
Knights Ferry, California