The Niagara Escarpment is a long escarpment or cuesta in the
United States and Canada that runs westward from New York State,
through Ontario, Michigan, Wisconsin and Illinois. It is composed
of the Lockport geological formation of Silurian age, and is
similar to the Onondaga geological formation, which runs parallel
to it and just to the south, through the western portion of New
York and southern Ontario. The escarpment is most famous as the
cliff over which the Niagara River plunges to form Niagara Falls,
for which it is named.
Niagara Escarpment
The Niagara Escarpment is the most prominent of several escarpments
formed in the bedrock of the Great Lakes. It is traceable from its
easternmost point in New York State, starting well east of the
Genesee River Valley near Rochester, creating a large (and two
small) waterfall on the Genessee River in that city, thence running
westwards to the Niagara River forming a deep gorge north of
Niagara Falls, which itself cascades over the escarpment. In
Southern Ontario it stretches along the Niagara Peninsula hugging
close to the Lake Ontario shore near the cities of St. Catharines
and Hamilton where it takes a sharp turn north toward Georgian Bay.
It then follows the Georgian Bay shore north-westwards to form the
spine of the Bruce Peninsula, Manitoulin, St. Joseph Island and
other islands located in northern Lake Huron where it turns
westwards into the Upper Peninsula of northern Michigan, south of
Sault Ste. Marie. It then extends southwards into Wisconsin
following the Door Peninsula and then more inland from the western
coast of Lake Michigan and Milwaukee ending northwest of Chicago
near the Wisconsin-Illinois border.
From this location you will be able to see inside the
escarpment. The bridge crosses the gap made by the entrance to a
local quarry and allows the Bruce Trail to continue un-interrupted
through the area. Looking out over the quarry you will be able to
see back in time many thousands of years by looking at the
cross-section of the exposed limestone.
As an experiment, measure the distance from the bridge to the
base of the quarry by estimating the distance vertically, and then
measuring it horizontally using your GPS.