In 1743-44 he may have travelled southwest to what was probably Wyoming and came within sight of the Rocky Mountains. The documentation is poor and it may have been a different Vérendrye brother who made the journey.
Commandant posts
By late 1743, Louis-Joseph's father, Pierre La Vérendrye, was forced to resign as commandant of the poste de l’Ouest. The new commandant, Nicolas-Joseph de Noyelles de Fleurimont, retained the services of La Vérendrye’s sons during his tenure, which began in 1744. Louis-Joseph was post commander at three posts, the most important one being Fort Kaministiquia. The elder La Vérendrye again became western commandant in 1747, while Louis-Joseph returned to New France with Noyelles. He provided services to both Noyelles and Governor Beauharnois while expecting and intending to rejoin his father at the western posts. Before he made that return, his father returned east and died in 1749. Louis-Joseph spent the next several years settling his father's financial affairs, and subsequently entered into partnership with Luc de la Corne in the fur trade. His brother François was an interpreter for the partnership. The claim that he reached the Saskatchewan River Forks in 1749 may be false. In 1756, Louis-Joseph obtained a three-year appointment as commandant of the poste de l’Ouest. He carried out this enterprise through agents, as he was personally involved in military matters during the Seven Years' War. He was succeeded as western commander in 1758 by Charles-René Dejordy de Villebon. After the conquest of Quebec he died while returning to France, when his ship, the Auguste, sank off Cape Breton.
De la Verendrye is one of the main characters of the Ubisoft videogame Assassin's Creed Rogue, where he is a member of the Assassin Brotherhood. He is portrayed as being short-tempered, brusque, and egotistical, consistently referring to protagonist Shay Cormac as a 'cabbage farmer'. When Shay defects to the Templars, de la Verendrye uses his warship, Le Gerfaut, to bombard and heavily damage Master Assassin Achilles Davenport's homestead. In the game's penultimate mission, Shay, Master Templar Haytham Kenway, and James Cook chase de la Verendrye off the coast of Newfoundland, who is escaping with maps leading to the Precursor sites the Assassins and Templars seek. Shay eventually boards Le Gerfaut and gravely wounds de la Verendrye before angrily leaving him for dead by throwing him off the ship and into the freezing waters.
