Bellevue Spillway

Steven Dutch, Professor Emeritus, Natural and Applied Sciences, University of Wisconsin - Green Bay

---

The Bellevue Spillway is one of a series of puzzling gaps in the Silurian (Niagara) Escarpment. Well records show that these gaps are deep bedrock valleys, but they have little topographic expression. They are mostly filled with glacial deposits, but they are crossed by shallow eroded valleys. They are probably relics of a pre-Pleistocene drainage system that were mostly filled by glacial debris, but served as short-lived outlets for Glacial Lake Oshkosh.

	The map shown here shows the head of the spillway.
	Along Highway 29, the only expression of the outlet is a shallow dip.

Eaton Road

	Few roads cross the spillway near its head. Eaton Road is the first crossing that provides a good view of the upper channel. The best views of the channel would be from along the railroad tracks that run along its west side. The Neshota River, which flows southeast to Lake Michigan, begins just east of the road. This map area overlaps the maps shown above.
.	A view north along Eaton Road. The black rectangle is the railroad bridge.

Pine Grove Road

	Good views of the spillway are obtained from Pine Grove Road and Phillips Road. Lilly Lake in the northeast corner of the map is one of a chain of kettle ponds in deep glacial deposits.
	Looking east along Pine Grove Road (County T) the size of the spillway is obvious
	A view north across the spillway along Phillips Road
	The east side of the channel seen from Phillips Road. The flat bottom and abrupt slope break suggest that the spillway carried a substantial volume of water, if briefly.

---

Return to Geology of Wisconsin Index
Return to Geologic Localities Index
Return to Professor Dutch's Home Page

Created 19 May 1999, Last Update 11 Jan 2020