Captain Sanders, in the forties, had estimated that it cost about fifteen dollars to remove each ordinary snag from the Ohio. In the Mississippi the roots of snags could be thrown into the deep pools where they would soon become buried in mud; but on the Ohio such pools were not frequent and it was usually necessary to carry the roots ashore and destroy them with gunpowder. Sanders reported that up to September 1837 there had been three thousand three hundred and three obstructions removed from the Ohio. In 1839 there had been about ten thousand removed; at which time the work ceased. Some of the snags were six feet in diameter at the butt and over one hundred feet in length. In a report in 1835, on Mississippi improvement, Lieutenant Bowman stated: "It is a well-established fact that snags do not move far from where they first fall in, the weight of the earth attached to their roots serving as an anchor. It is also well established that trees which once float seldom form snags. Admitting this, it is sufficiently evident that if the banks are once cleared, there can be no subsequent formation of snags." Second only to such obstructions was the "Falls of the Ohio," the one spot in all its course of nearly a thousand miles where steamboat navigation was impossible until the construction of a canal, which followed the route of the ancient portage path two and one-half miles in length between the present sites of Louisville and Shipping-port, Kentucky. In this distance the Ohio makes a fall of about twenty-five feet caused by a ledge of rocks extending across the river. Steamboating is impracticable here save only when the river is at flood-tide. A company was incorporated by the legislature of Kentucky to cut a canal around the falls in 1804, but nothing was done until January 12, 1825, when the Louisville and Portland Canal Company was organized, with a capital of $600,000. The stock was taken by about seventy persons, residing in Kentucky, Ohio, Missouri, New Hampshire, Massachusetts, New York, Pennsylvania, and Maryland, the United States holding 2,335 shares, and 1,665 issued to private individuals. Many difficulties attended the construction of the work, which was not completed until December 5, 1830. During the year 1831 406 steamboats, 46 keel-boats, and 357 flat-boats, measuring 76,323 tons, passed through the locks.[76]