In the late 19th century, the Ica was navigated by the French explorer Jules Crevaux (1847-1882). He ascended it in a steamer drawing 6 feet of water, and running day and night. He reached Cuemby, 800 miles above its mouth, without finding a single rapid. Cuemby is only 200 miles from the Pacific Ocean, in a straight line, passing through the town of Pasto in southern Colombia. Creveaux discovered the river sediments to be free of rock to the base of the Andes; the river banks were of argillaceous earth and the bottom of fine sand.