They are also used for the German Oktoberfest
The Irish-American community would like to thank the
German-American community and the town of Irondequoit for their use.
The valleys were cut during the early Holocene (9,000-8,000 years
ago) after Glacial Lake Iroquois had drained, before the land had rebounded
from the weight of the Pleistocene icesheets, and before global sea level
had returned to its present level (much water was locked up in the still-sizable
icesheets). Lake level was very much lower and the beach much further north,
so local streams cut down into the land for hundreds of years. As the St. Lawrence
River Valley rebounded from the weight of the ice, it kept more and more
water in the Ontario basin. Gradually the stream valleys were flooded
and stopped eroding downward. Beaches migrated along shore to put bars in
front of the stream mouths and these bars were stabilized as causeways
through the 19th and 20th centuries.