This important route from Illinois to Detroit was first fortified by the building of the earliest "Fort Miami," near the mouth of the St. Josephs of Lake Michigan, by La Salle in 1679. "But this fort," Mr. Reuben Gold Thwaites writes, "was destroyed by La Salle's men in 1680. Father Jean Mermet, then at the river [St. Joseph] mouth, writes La Mathe Cadillac, April 19, 1702, that he proposes to establish a mission 'three journeys,' or about sixty miles up river, 'near a stream [Illinois] which is the source of the Ouabache,' where there is a portage of half a league (_Margry_, v, p. 219). In 1711, Father Chardon had his mission sixty miles above the mouth. By 1712, there appears to have been a French military post at this mission. Charlevoix, in a letter dated 'River St. Joseph, Aug. 16, 1721,' writes, describing his approach to the fort from Lake Michigan: 'You afterward sail up twenty leagues in it [up the St. Josephs River] before you reach the fort, which navigation requires great precaution.'... The evidence is ample, that the fort on the St. Josephs, from about 1712 to its final destruction during the Revolutionary war, guarded the portage between the river of that name and the Kankakee, on the east bank of the St. Josephs, in Indiana, a short distance below the present city of South Bend."[86] The Kankakee-St. Joseph route was a favorite one for travelers returning from Illinois to the Great Lakes and Canada. The favorite early "outward" route was from the western shore of Lake Michigan into the Illinois River. Here were two courses: by way of either the Calumet or the Chicago River to the Des Plaines branch of the Illinois. The latter portage was best known and most used. Perhaps no one of the western portages varied more than this in length, as on the best authority it is asserted that sometimes no portage was necessary, and at others a portage of nine miles was necessary: "The Chicago--Des Plaines route involved a 'carry' of from four to nine miles, according to the season of the year; in a rainy spring season, it might not be over a mile; and during a freshet, a canoe might be paddled over the entire route, without any portage."[87] When Marquette reached the Des Plaines, known as "Portage River" because it offered a pathway to the Illinois, he was compelled to make a portage of only "half a league."[88] The course of this portage is practically the present route of the famous Drainage Canal which joins the Chicago River with the Des Plaines at Elgin, Illinois.