Number 123 July 10, 1922
Ann Arbor, Michigan Published by the University
Three natural physiographic divisions cross Washtenaw County fromnorthwest to southeast. The northwestern part of the county is occupiedby the rough interlobate moraine of loose-textured soil, the InterlobateLake District; a broad Clay Morainic Belt occupies most of the centralpart of the county; and in the southeastern corner of the county isfound a low Lake Plain, once the bed of glacial Lake Maumee.
The Interlobate Lake District has a conspicuous system of moraines,making up a most irregular land surface. Steep knolls 100 to 200 feet inheight are closely associated with basins, which are often deep, andsome of which are occupied by lakes. Small, undrained depressions occureverywhere, producing thousands of acres of swamp and marsh land.
The Clay Morainic Belt occupies the region from just below Portage Laketo Ypsilanti. It is composed of glacial till plains[Pg 2] and clay morainesextending from northeast to southwest. This area includes the highestland in the county, one hill exceeding and several approaching 1100 feetin altitude. Most of the area is high and rolling.
The old beach, marking the limits of the Lake Plain District, runsnortheast from Ypsilanti to the county line above Cherry Hill, andsouthwest through Stony Creek to a point on the county line about eightmiles west of Milan.
The native upland forests of the Interlobate Moraine District werecomposed chiefly of red, yellow, and white oak, with some smooth-barkhickory and sugar maple and a few shag-bark hickories. Here were alsolarge areas of creeping juniper and a few small patches of groundhemlock (yew). On the flood-plains of the rivers and lakes were quiteextensive swampy forests of soft maple, black ash, and white elm. Swampoak and whitewood grew commonly in the drier situations toward the edgeof the swamp conditions. The red-bud and red cedar were characteristicof the river banks. White pine probably never grew in the county,although a few trees occur on the south bank of the Huron River nearHamburg, a few miles north of the county line.
Tamarack bogs, some of large size, are abundant in the InterlobateMoraine District and occur commonly also in the Clay Morainic District,but are practically wanting in the Lake Plain District.
The Clay Morainic District was originally dominated by forests of oakand hickory. Several kinds of oaks, white ash, and several species ofhickories, with shag-bark most characteristic, were most abundant. Mixedwith these were elm, beech, sugar maple, black walnut, and butternut. Onthe higher ground many stands of quaking aspen were found. The forestwas quite dense and little underbrush normally[Pg 3] occurred. Tamarack bogswere common, and a small stand of black spruce occurred at the edge ofIndependence Lake. There are few flood-plains along the Huron River inthis district, but along the river's edge were a few cottonwoods andsycamores, and many willows, some of large size. On the steep bluffsalong the river was often a heavy growth of red cedar; and some largeareas of procumbent juniper occurred. In this district were severalopen, level, sandy plains covered with a scattered growth of white andbur oaks and an undergrowth of hazel brush. These were