Near Trempealeau in Trempealeau County, Wisconsin — The American Midwest (Great Lakes)
The Geology of Perrot State Park
Millions of Years Ago
Millions of years ago, Trempealeau Mountain, the bluffs of Perrot State Park, and the Minnesota upland across the river were all one continuous rock mass. Over time, Cedar Creek, Big Trout Creek, and their tributaries carved channels that would isolate Trempealeau Mountain. This drawing shows that the Mississippi River ran north of the park.
During the last part of the Ice Age, some 50,000 years ago, glacial meltwaters laden with sand, gravel, and debris blocked the river's previous route. This forced the Mississippi River to seek a new channel. This drawing shows how this diversion shifted the boundary between Wisconsin and Minnesota. We can thank the glacier for giving Wisconsin the gift of Perrot State Park.
Location. 44° 1.398′ N, 91° 29.22′ W. Marker is near Trempealeau, Wisconsin, in Trempealeau County. Marker can be reached from South Park Road. Click for map. Marker is in Perrot State Park (fee area) at a vista near the Black Walnut Nature Trail parking area. Marker is at or near this postal address: W26247 Sullivan Road, Trempealeau WI 54661, United States of America.
Other nearby markers. At least 8 other markers are within 7 miles of this marker, measured as the crow Brady's Bluff (approx. 0.7 miles away); Perrot's Post (approx. 0.9 miles away); French Post (approx. 0.9 miles away); James Allen Reed / Trempealeau (approx. 2.6 miles away); Pickwick Mill (approx. 3 miles away in Minnesota); Historic Lake Labelle (approx. 3 miles away in Minnesota); The Mississippi River Parkway: (approx. 3.4 miles away); Sugar Loaf Bluff (approx. 7 miles away in Minnesota). Click for a list of all markers in Trempealeau.
More about this marker. Wisconsin map caption:
Maximum extent of glacial ice in Wisconsin. Glacial meltwaters shaped the landscape at Perrot State Park, not glacial ice.
[red triangle] You are here
[yellow] Limestone bluffs formed from sediment deposited by shallow seas over 450 million years ago
[white] Flood Plain
Also see . . .
1. Perrot State Park's Geology. (Submitted on August 30, 2011.)
2. Trempealeau Mountain (No. 356). "Surrounded by the Mississippi and Trempealeau Rivers, the steep-sided Trempealeau Mountain is one of only three solid rock islands along the entire stretch of Mississippi River." (Submitted on August 30, 2011.)
Categories. • Natural Features •
Credits. This page originally submitted on , by Keith L of Wisconsin Rapids, Wisconsin. This page has been viewed 503 times since then and 12 times this year. Photos: 1, 2, 3, 4, 5, 6, 7. submitted on , by Keith L of Wisconsin Rapids, Wisconsin. This page was last revised on June 16, 2016.