The town was started in 1855 , at the head of navigation on Fresno Slough . A pier was built to accommodate flatboats and barges that could make it up the shallow slough . Warehouses , houses , and the Casa Blanca Hotel were built . In 1858 , it became a station on the Butterfield Overland Mail . By 1860 , the telegraph line from San Francisco arrived . Plans for a much larger town were contemplated but the Butterfield line closed in early 1861 , the Great Flood of 1862 did great damage and the City was practically abandoned by 1865 . A post office operated at Fresno City from 1860 to 1863 . Today there are no traces of it left
Great Flood of 1862
Great Flood of 1862
Fresno City, California