In the summer of 1731, La Verendrye started west by the Grand Portage; and in the next eight or nine years established posts along the water line, from Rainy Lake to where the Saskatchewan river enters Lake Winnipeg from the north-west. One of these forts or stations was Fort La Reine on the Assiniboine river, which formed the starting-point for an advance over the western plains through what is now the State of Dakota. In 1742, two of his sons made their way from the Assiniboine to the Missouri, crossed the latter river, and, traversing the prairies in a westerly and south-westerly direction, reached the country drained by the tributaries of the Yellowstone river. How far they went is matter of conjecture, and doubt is thrown on their claim to have been the first discoverers of the Rocky mountains. It is stated that, on January 1, 1743, they came in sight of high mountains, which are supposed to have been the Bighorn range in Wyoming and Montana, an eastern buttress of the Rocky mountains, lying in front of the Yellowstone National Park; but no mention is made in the story of snowy peaks, such as would indicate discovery of the great mountain barrier of America. The explorers {214} came back in fifteen months' time. Their father died in 1749, and, like other pioneers, they reaped but little fruit, in honour or in profit, from all their labours. They did not find the western sea, they possibly did not descry the Rocky mountains; but to La Verendrye and his sons it must be credited that a new water area in the far west was fully made known to the world, and that trade routes were opened beyond the basin of the St. Lawrence and the basin of the Mississippi, reaching to the great Saskatchewan river and to the waters which flow into Hudson Bay. [Sidenote: _The Rocky mountains._] The Rocky mountains, as we know them, were not known in the eighteenth century.[10] In 1793 Sir Alexander Mackenzie crossed them far in the North, by the line of the Peace river, and reached the Pacific Ocean on the coast of British Columbia; but the full revelation of the main range dates from the year 1805, when Lewis and Clarke followed the Missouri to its source, and thence made their way over the mountain barrier to the western sea. In short, as long as Canada was New France, and for years afterwards, it was for trading and for colonizing purposes a region of inland waters; it was not also, as it now is, a land of plains, with a background of giant mountains, and behind them the further ocean. Yet it was to reach the further ocean that Europeans first came into Canada, and the earnest expectation of the earliest {215} explorers has in our own time found more than fulfilment in a Dominion from sea to sea.