Seine Commercial craft (barges and push-tows) can use the river from Marcilly-sur-Seine, to its mouth. At Paris, there are 37 bridges. The river is only above sea level from its mouth, making it slow flowing and thus easily navigable. The Seine Maritime, from the English Channel at Le Havre to Rouen, is the only portion of the Seine used by ocean-going craft. The tidal section of the Seine Maritime is followed by a canalized section ("Basse Seine") with four large multiple locks until the mouth of the Oise at Conflans-Sainte-Honorine (170 km). Smaller locks at Bougival and at Suresnes lift the
Steamboats of the Colorado River Fort Yuma at Jaeger's Ferry. In 1858, 1 mile above Colorado City, across the river from Fort Yuma, Arizona City was founded, (renamed Yuma in 1873). In 1865, a better location for an anchorage, and a port and shipyard was established at Port Isabel, Sonora, 157 miles below Fort Yuma and 7 miles east of the river mouth on the eastern outlet of the river. In 1873, Lerdo Landing appeared on the river, 3 miles above Port Famine, to connect the pioneering agricultural settlement of Colonia Lerdo to the steamboat traffic on the river. Port Isabel remained in use until