My retirement hobby has been "topology", topographic studies of places in relation to their histories. I take a primary source describing someone's travel in and about Michigan centuries ago and; using my extensive topographic map collection, library research and road reconnaissance, work out their route.
All I or anyone else knows about LaSalle's 1680 walk across the Lower Peninsula is contained in a single letter he wrote to an investor back in France in September of 1680. The sole and primary source on Hugh Heward's 1790 expedition from Detroit to the Mississippi is his detailed journal which fortunately has been preservred and published.
Here is a story about both of them based on their own words.
Robert Cavelier, Sieur de LaSalle, the famous French explorer who built and navigated the first sailing ship on the Upper Great Lakes was the first white man to go down the Mississippi to its mouth. In 1679 and 1680 he traveled on, up, down, across and along Michigan waters and actually walked across the Lower Peninsula.
In 1790 British trader Hugh Heward and his party of seven French-Canadian paddlers in two birchbark canoes traveled from Detroit down the Detroit River to Lake Erie then went up the Huron Riiver and a tributary to a portage that took them into the Grand River valley. Then they went down a tributary and the Grand to Lake Michigan and along the shore to the Chicago River. They then portaged into the Illinois River system and followed the Illinois all the way to the Mississippi.
In so doing they crossed or traveled on LaSalle's paths of 110+ years before several times. Example: In 1679 LaSalle sailed up the Detroit River in his ship Griffon while in 1790 Heward's party paddled down the Detroit River in their birchbark canoes. Here in bits and pieces are some of their coincidents (is that a word?).
In 1678 and 1679 LaSalle caused to have built adjacent to the Niagara River a sailing ship to be known as theGriffon. In the summer of 1679 the ship, loaded with trade goods; sailed across Lake Erie, up the Detroit and St. Clair Rivers and Lake Huron, through the Straits of Mackinac and across northern Lake Michigan to an island at the entrance of Green Bay. There they took aboard a load of furs and the Griffon departed to return to Niagara.
After the Griffon departed, LaSalle with 14 men in four canoes embarked on an arduous journey around the west and south shores of Lake Michigan to the mouth of what he called the River of the Miamis. They built a small fort on the bluff overlooking the lake at the site of present-day St. Joseph (my wife Elaine's home town). There would have been four paddlers in three of the canoes and three in the other one. Thus their canoes were probably about the same size as Heward's, 20 footers.
In April and May of 1790 the Heward party traveling south along Lake Michigan's east coast from the mouth of the Grand River arrived at the mouth of the St. Joseph River. From then on they traced LaSalle's path in reverse as far as the Chicago River.
In the fall of 1679 LaSalle's party went upstream on the St. Joseph River as far as present-day South Bend and made a five mile portage into the marshes that were the headwaters of the Kankakee River. They followed down the Kankakee to its junction with the Des Plaines River where the two conjoined rivers became the Illinois River. Then they paddled down the Illinois to a place south of present-day Peoria where they built a fort that LaSalle called Crevecoeur (broken heart). They spent the winter of 1679-80 working on a ship they hoped to use to explore the Mississippi River, which had been discovered by Marquette and Joliet seven years earlier.
When the Heward party arrived at the Chicago River in the spring of 1790 they went up that river to the portage to the Des Plaines River. There they traded their two canoes for a pirogue (dugout canoe) and hired Indians to carry their gear and goods across the portage. They launched their pirogue and headed downstream (south) on the Des Plaines to its junction with the Kankakee then followed the Illinois all the way to the Mississippi From the confluence of the Kankakee and the Des Plaines to where they passed the site of Ft. Crevecoeur they were following LaSalle's 1679 route.
They were also going in the opposite direction on the Illinois on the route taken by Marquette and Joliet when they were returning in 1673 from "discovering" the Mississippi (the Indians already knew where it was). In 1675 Father Marquette was dying as he was being paddled by a single companion along the Lake Michigan shore from the Chicago River trying to get back to his mission at St. Ignace. He didn't make it. He died along the way, probably near present-day Ludington by the lake that bears his name. Thus both LaSalle in 1679 and Heward in 1790 traced Marquette's path.
If you visit me at my display at the Quiet Water Symposium March 7 I have this all on a big map.