"Le Griffon" was constructed and launched at or near Cayuga Island on the Niagara River and was armed with seven cannons. The exact size and construction of Le Griffon is not known but many researchers believe she was a 45-ton barque. She was the largest sailing vessel on the Great Lakes up to that time. La Salle and Father Louis Hennepin set out on "Le Griffon"s maiden voyage on 7 August 1679 with a crew of 32, sailing across Lake Erie, Lake Huron and Lake Michigan through uncharted waters that only canoes had previously explored. The ship landed on an island in Lake Michigan where the local tribes had gathered with animal pelts to trade with the French. La Salle disembarked and on 18 September sent the ship back toward Niagara. On its return trip from the island, said to be located in the mouth of the body of water which is now known as Green Bay, it vanished with all six crew members and its load of furs.