Finishing my 1999 "Michigan History" article:
The construction of the canoe required cutting down a large elm tree---a formidable task with the hatchets the party were carrying. It was also challenging to strip the bark from the tree in one piece without breaking it or cracking it to the point where it would be unusable. The tree would have been either a slippery elm or an American elm. LaSalle, who called the tree by its Iroquois name of arondugalte recorded, "The bark of which can be stripped off at all times though with more difficulty at this season, when it must be continually moistened with boiling water".
To make a canoe from a large cylinder of elm bark, the ends are squeezed together and sewn with strips of bark or roots; gunwhales of saplings, split or whole, are attached in the same manner. Then stick thwarts are inserted at intervals to spread the bark, and ribs of some flexible wood are inserted on the inside. Finally the insides of the ends are caulked with the bark of dead slippery elm, which swells when wet.
Why not build a birchbark canoe? The Huron lies below the southern limit of where the paper birch grew. Although a birchbark canoe is far superior in most respects to a canoe of elm or hickory bark, its construction takes a lot of time, skill and experience---which neither LaSalle nor his men possessed.
With the canoe completed and the sick men and all gear on board, the journey down the Huron began. All did not work out as hoped. As LaSalle described the trip, "For as the river was everywhere encumbered by heaps of wood, which the swollen waters carry down or cast into its bed, we got weary of carrying our baggage every moment when the masses of wood prevented the canoe from passing; moreover the river made wide bends, and we observed after five days of rowing we had made less progress than we normally made in one day's march." So they gave up on floating down to Lake Erie and, according to LaSalle, "...our sick men being better, we resumed our march and reached the strait by which Lake Huron falls into Lake Erie which is a league broad at this place".
The "strait" is the Detroit River and LaSalle and his men reached it downstream of Grosse Isle and upstream of the extensive swamps and marshes where the Huron empties into Lake Erie. Here the Detroit River is more than three miles wide, which is reasonably consistent with LaSalle's estimate.
A little arithmetic can provide a clue as to where the men abandoned their canoe and resumed walking. LaSalle equated five days on the Huron to one day's march, and one can assume a day's march to be about thirty miles. This about the distance from Dexter to the area near Belleville where the Huron makes a big bend to the south (French Landing). I think this is where the party gave up poling, paddling and portaging. They would have followed the left bank of the river on foot down to about present-day Rockwood. By heading straight east from there they would have avoided the drowned lands at the mouth of the Huron and reached the Detroit River south of Grosse Isle.
There two men were tasked to build a canoe and head north to Michilimackinac, while LaSalle and the remaining three rafted across the river. They continued cross country to the shore of Lake Erie, probably just beyond Pte. Pelee, where another canoe was built. Then the Frenchmen and Saget, the Indian, paddled along the shore to Niagara. They arrived there on Easter Sunday, April 22, 1680.
As Professor Prator concluded more than half a century ago, "We shall probably never be able to retrace the great Frenchman's steps with absolute accuracy". There is no archaeological evidence and only LaSalle's one letter documenting the trip. However, given the availability of modern topographic, presettlement vegetation and soil survey maps, we have far better technical resources at our disposal than did earlier writers. Further, if one conducts serious on-the-ground reconnaissance, visualizes things as they were three hundred years ago and carefully matches LaSalle's descriptions to the existing terrain, it is possible to retrace his steps with reasonable accuracy. Finally, we do know one other thing----LaSalle and his companions crossed the Lower Peninsula the hard way.
This is the end of my 1999 article. I will follow up with some remarks on his route pertinent to the Relay idea and a chronology of LaSalle and Michigan's history.