Louis Hennepin was likely born in 1640, although some sources suggest it was as early as 1626. The son of a wealthy banker, he was baptized in the small town of Ath in what is now Belgium on April 7, 1640. Hennepin joined the Recollect Friars at a monastery in Béthune, France, and was ordained a priest in 1666. A few years later, he asked his superiors for permission to join the Recollect missionaries in North America. In 1675, he sailed to Quebec.
The Recollects were a French branch of the Franciscan order were active throughout France’s territory in North America. Hennepin spent his first three years as a missionary in the area of the eastern St. Lawrence River, ministering to voyageurs, colonists, and American Indian communities. In 1678, he was chosen to accompany René-Robert Cavelier Sieur de la Salle on his exploration of the Mississippi. In 1680, while on La Salle’s expedition, Hennepin and two other members of the party, Michel Accault and Antoine Auguelle (Picard du Gay), were sent to explore the section of the Mississippi north of the Illinois River.
Fort Frontenac was a French trading post and military fort built in 1673 at the mouth of the Cataraqui River where the St. Lawrence River leaves Lake Ontario (at what is now the western end of the La Salle Causeway), in a location traditionally known as Cataraqui. It is the present-day location of Kingston, Ontario, Canada. The original fort, a crude, wooden palisade structure, was called Fort Cataraqui but was later named for Louis de Buade de Frontenac, Governor of New France who was responsible for building the fort.
The British destroyed the fort in 1758 during the Seven Years’ War and its ruins remained abandoned until the British took possession and reconstructed it in 1783. The fort was turned over to the Canadian military in 1870–71 and it is still being used by the military.
He had a Journal and did rough sketches of which I am searching for.
Also there is this accounting of his travels.