The Au Sable River

Part 1:  The Au Sable River: The Lifeblood of the Twin Communities of Au Sable and Oscoda, Michigan    

David K. Vaughan 


The Au Sable River just above Five Channels Dam, looking west.

The Au Sable River is the largest river on the northeast coast of Michigan’s lower peninsula north of Saginaw Bay.  Its source is a small lake in the north center of the lower peninsula of the state of Michigan, on the southern edge of Otsego County, where it is a small, winding, marshy stream that meanders slowly southward, gaining size and strength as other small tributaries feed it.  Just a few miles to the west a similar stream meanders slowly to the south through a series of small lakes. As these two small streams approach the town of Grayling, they turn in opposite directions.  The westernmost stream, the Manistee River, flows to the southwest, eventually flowing into Lake Michigan.  The easternmost stream, the Au Sable River, flows to the southeast.  At Grayling, it turns east and continues in an easterly direction for forty miles.  Then it turns south again, passing six miles southwest of Curran and three miles west of Glennie.  When it reaches the High Rollways about five miles south of Glennie, it turns east again for the final run into Lake Huron, effectively dividing the twin coastal communities of Oscoda and Au Sable.  The High Rollways are so named because they consist of a high bluff that runs along the south side of the Au Sable for several miles, ending about two miles east of the last power dam on the river, Foote Dam.  Although the straight line distance from Grayling to Oscoda is about 80 miles, the Au Sable River is estimated to cover twice to three times that distance as it winds through the forested hills that lie between Grayling and the mouth of the river, where it enters Lake Huron.

The drainage pattern of the Au Sable is unusual in that the drainage area of the river’s source is much larger than the drainage area at the river’s end.  Of the approximately 2000 square miles of drainage area, about two-thirds of that area is located around and along the western or interior half of the river, the source area, and one-third is located along the eastern half.  The source area is essentially a wide, shallow bowl from which source waters drain from all directions.  The river then breaks gradually through the eastern edge of its western basin and descends into the more gradual eastern slope.  The drainage area decreases gradually as the waters proceed to the mouth of the river, and in the final twenty miles of the river’s length the drainage channel becomes very narrow, measuring in some sections a mere half-mile north or south from the river’s edge.

Although the mouth of the Au Sable River today presents a relatively straight channel stretching inland from Lake Huron, essentially dividing the two towns of Oscoda (to the north) and Au Sable (to the south), it was not always so.  An aerial examination of the land just one mile upriver from the river’s mouth shows clear evidence of the historical difficulty the river experienced in finding its final outlet to the lake.  A section called the “Dead Au Sable,” for instance, is a winding channel that leads two or three miles to the south, paralleling the shoreline of Lake Huron about a quarter of a mile inland before finally feeding into the lake some two miles south of the present mouth of the river.

But even before the river reached the “Dead Au Sable” channel, it wound around in a series of curves and turns in a frustrated effort to reach the lake.  A section of Oscoda referred to as Hull’s Island was originally a large ox-bow bend in the river that curved to the north, east, south and west, before the river was able to break through to Lake Huron.  It is almost as if the river were a large snake that twisted and turned repeatedly, looking for an opening in an impenetrable barrier, before it was able to find a path to the lake.  This twisting, turning feature of the river as it neared the lake directly affected the development of lumbering operations in Au Sable and Oscoda.

The Au Sable River is the largest and longest river emptying into the western shore of Lake Huron.  Its mouth is located between Saginaw, some eighty miles to the south, and the Straights of Mackinac, some hundred and fifty miles to the north.  The best-known lumbering river on the eastern side of the state is the Saginaw River, long famous in lumbering song and legend.  The Saginaw River itself is actually relatively short, only about ten miles long; its lumbering fame resulted from the lumber brought into it primarily by the much longer rivers which fed into it, including the Tittabawassee River, which extends from Saginaw well north into the central highlands of Michigan’s lower peninsula.  Other rivers also feed the Saginaw, including the Shiawassee, the Flint, and the Cass Rivers, but these relatively short rivers brought fewer logs to the Saginaw lumber mills than the Tittabawassee.  Most of the lumber processed on the Saginaw came from the forest lands bordering the Tittabawassee and its smaller tributary, the Tobacco River.  Certainly the lumbering history of Michigan can be said to have begun with the pioneering sawmill cities of Saginaw and Bay City.  But once the pine trees that fed the sawmills of the Saginaw began to thin out, the lumbering interests looked farther north, first to the regions north of Saginaw, and then eventually to Michigan’s upper peninsula.

The Au Sable River was recognized early as an important avenue to lumbering prosperity.  It was almost perfectly suited to the needs of the lumbermen.  Long, relatively wide, and modestly deep, meandering through miles and miles of tall red pine and white pine trees, it was the perfect transportation system for bringing the cut logs out of the Michigan forests to the sawmills that soon developed in the town of Au Sable.  Although one source says that the length of the river from Grayling to Oscoda is 129 miles, that distance would have been much longer in the lumbering days, before six power dams were erected on the river in the early 1900s.  The ponds that were created by these dams eliminated many of the winding curves that were a part of the river’s original path.  Its winding route to Lake Huron assisted the lumbermen as much as it hindered them, for while its curving course required more time to bring the logs down the river, it also allowed them to access the river from a variety of directions and provided a greater number of locations for logs to be stacked alongside the river as it wound through the wooded lands that bordered the river.

Narrow at its source, by the time it turns from its initial southerly heading to an easterly heading at Grayling, it soon expands its size through the contribution of three main branches: the East Branch, the South Branch, and the North Branch.  These three branches, which enter the river within a relatively short stretch of fifteen road miles, expand the water flow of the Au Sable significantly.  The East Branch enters the Au Sable first, on the east side of Grayling.  The South Branch joins next, about eight miles east of Grayling, winding on a northeast direction from Roscommon.  The North Branch enters soon after, about four miles later, coming straight down from lakes on the southern edge of Otsego County.  By the time the river flows past Mio it has reached something like a steady state of width and depth, with many creeks feeding it but few streams of significant size flowing into it until it nears Lake Huron.

Other sources bring water into the river; literally thousands of springs burble, run, or seep into the river along its entire length.  On a day when the winds are calm, canoeists floating down the Au Sable River from Mio past McKinley to the beginning of the pond behind the Alcona Dam can hear these springs entering the river at every turn.  Their waters are clear, cool and fresh; in earlier days metal cups would hang from trees or bushes near the springs, left by a passing canoeist or fisherman to be used by thirsty visitors.  Individually small, each spring contributes to what must be an enormous output.  This special characteristic of the Au Sable contributes to its steady volume of water, and though it is affected, like all rivers, by rainfall, snowfall, and drought, the volume of water that flows between its banks throughout the year is wonderfully consistent.

The remarkably clear, unmuddied nature of the water that flows in the Au Sable results from geological features of the land through which it flows as well as the fresh springs that feed it.   Geology texts state that the northern portion of Michigan’s lower peninsula was covered first by a sea and then by thick glaciers in earlier ages.  The effect of these seas and glaciers was to create a depression in the earth’s surface that eventually filled in with various layers of sediment.  The Au Sable River moves mostly across gravel and sand beds which resulted from the action of glaciation as the glacial ice moved and melted.  These beds produce a scrubbing, or cleansing effect on the waters as they flow, resulting in the cleanest river water of any major river in Michigan and possibly the United States.

The common practice of residents of Michigan when describing the state to non-residents is to hold up their right hands, palm outward, to indicate in which part of the lower peninsula they live.  This image conveniently illustrates the features of the geology of the area.  If we look at the palm of our right hand, we will see an indentation, and if we imagine that indentation extending to the middle knuckles of the fingers, we will have a reasonably accurate means of visualizing the shape of the hard crust of the earth below the earth’s surface.  This geological feature gives the Au Sable River (and its companion river on the west side of the state—the Manistee River) its special qualities.  The same forces that push water out of the ground and into the Au Sable River extend in an arc to the west approximately following the course of the Manistee.  Evidence of this phenomenon on the west side of the state can be seen, for example, in the natural springs that occur in the area around Manton, Michigan.

Today the original course and size of the river has been significantly altered by the construction of six dams constructed in the early 1900s to provide electrical power: in order from west to east, they are the Mio Dam, Alcona Dam, Five Channels Dam, Loud Dam, Cooke Dam, and Foote Dam.  Behind each of these six dams lie ponds of extended size and depth.  The ponds behind the final three dams on the river—Loud, Cooke, and Foote—are of such size that they essentially have created one long, narrow lake separated by the dams, flooding the river valley and eliminating the twisting course of nearly a third of the original river.

The Au Sable River was practically the ideal river for lumbering purposes: large enough, deep enough, and with a consistent volume of water.  According to a recent source, the volume of water flow measured, on average, about 900 cubic feet per second below the Mio dam and nearly 2000 cubic feet per second at Oscoda.  These are modern measurements, of course, made after the construction of the dams, but it is probable that if measurements had been made in the late 1880s, they would be similar to modern measurements.  Especially in the upper reaches of the river, east of Grayling and prior to reaching the pond behind the Mio dam, modern waterflow measurements would be practically the same as experienced during the lumbering days, with about 75 cubic feet per second at Grayling and about 500 cubic feet per second above the Mio pond.  These figures show how waterflow benefits from the influence of the three branches of the Au Sable and other streams that feed into the river.  But they also suggest why the river was important to loggers, as it offered a regular and reliable means of floating the lumbering logs from the harvest areas down to the mills in Au Sable and Oscoda.

Lumbering began in earnest on the Au Sable River in the late 1860s, after the conclusion of the American Civil War.  Once the logs reached Au Sable and Oscoda, they could be trimmed, cut, and prepared for shipment to distribution centers in larger towns along the southern shores of the Great Lakes: Buffalo, Cleveland, Detroit, Chicago.  Shipping lumber from the mouth of the Au Sable to these population centers was relatively simple: initially there were two methods of moving the lumber to the markets.  Because initially there were few lumber mills located at the mouth of the river, the logs had to be rafted to larger cities, like Detroit, Cleveland, and even Buffalo, where they would be cut in the lumber mills.  Rafting the logs involved gathering a large number of uncut logs inside a chained perimeter of logs and towing them behind steam-powered vessels.  However, towing the rafts, even to local mills on the Lake Huron shore, could be a challenge in bad weather.

Soon lumber mills and docks were established at the mouth of the Au Sable River, where the lumber, cut in the mills located at Au Sable and Oscoda, could be loaded on boats, and the boats carried the lumber to cities where the demand for lumber was greatest; after 1880, the city with the greatest demand for lumber was Chicago.  Until the railroads came, in the late 1880s, there was no other practical method of moving the lumber to the mills except by water.

Not all Michigan rivers and streams were as suitable for lumbering operations as was the Au Sable River.  Many were relatively short, only a few miles long.  Many were small, with shallow river beds.  To use these streams, the lumbermen were forced to build small dams across the streams, effectively blocking the water from flowing.  Then after a winter’s worth of ice and snow had resulted in a substantial volume of water stored behind these dams, when the spring thaw came, they would release the water from the dams and the resulting torrent of water (and logs, which had been placed on or near the dams during the winter cutting season), would, they hoped, have sufficient force and volume to float the logs to the mills downstream.  But this system was slow, costly in terms of time and manpower, and terribly inefficient.  And it meant that at only one time of the year, during the spring thaw, could logs be floated downstream to the mill.

This procedure was not necessary on the Au Sable (though it was used on some of the smaller tributaries that fed the Au Sable in the upper forest basin above Mio).  Gradually, the lands bordering the Au Sable and the other streams were fully harvested, and the lumbermen moved farther away from the streams to find new stands of pine.  To move the cut trees to the river, the lumbermen used water sprinklers mounted on horse-drawn sleds to ice the track to the nearest river bank.  When the logging railroads came, logs could be loaded on flatbed cars and brought to the mill across the land without relying on the river.  But even after the railroad came to the northern areas of Michigan’s lower peninsula, the Au Sable River was still functioning as a useful transportation system for the lumbermen.

Although the lumbering days are long past, and evidence of the lumbermen’s presence is barely visible today, the Au Sable River is still the life blood of the communities of Au Sable and Oscoda.  The subsequent entries in this section of my web site will describe how the community activities and cultural habits of these two communities evolved from the beginning up to the present.  And throughout this historical chronicle of events, the Au Sable River lies at the heart of the narrative.