Ridged Landscape In This Area Formed By Glaciers Many Years Ago

Photo by Tony Angeloni A Spring afternoon view from Thrill Hill

A couple of weeks ago, this article was brought to my attention. The author thought it would be good to run it again and share the history of how this area was formed for those who may not be aware. Enjoy this Looking Back article from November 3, 1993.

Glaciation deposits are shown (black markings) on this map produced by the Illinois State Geological Survey.

By: Paul Willms
My fascination with the hill country in the Fayette County area began in the late ‘60s, while attending Brownstown Community High School. Sitting in the big study hall room daydreaming, I viewed a thin light-colored ribbon 10 miles to the west known as the Thrill Hill gravel road.
I always wondered why the land was so high and visible from that distance. A few years later, I found out why.
The catalyst for this article, Thrill Hill, lies northwest of Vandalia about two miles. It towers 655 feet above sea level and is one of the higher land formations in the country. It’s certainly no Pikes Peak, but it does have an impressive and panoramic view of the Kaskaskia River bottomland.
“Glacial Geology Of The Vandalia, Illinois Region” is the name of circular #442 published in 1969. Illinois State Geological Survey Geologists Alan M. Jacobs and Jerry A. Lineback completed an in-depth study of the land formations in the Vandalia region.
According to Jacobs and Lineback, several glaciers moved through the area in the last 1 million years. The times of glaciations were named after states Wisconsin, Illinoian, Kansan and Nebraskan. The glaciers eroded and deposited a variety of sediment from clay, silt, sand, gravel and till (a mixture that includes large rounded rocks) in a variety of land forms including hills.
During the 1960’s a model based on four glaciations was sufficient to explain the glacial history of the Midwest. Recent personal communication with the Illinois State Geological Survey staff indicates this concept has changed somewhat.
Since then, geologists have fine-tuned the explanation that expands the number to about 10 glaciations in the last million years. This has clouded the meaning of the old terms Kansan and Nebraskan, which are no longer used.
The last glacier, named after Wisconsin, terminated near Shelbyville about 20,000 years ago. Meltwater from the glacier formed the present features in the Kaskaskia Valley. The next to last glacier named Illinois, created the landform of the Vandalia region and reached its limit at St. Louis about 140,000 years ago.
The time period after the last glaciations is know as the Holocene and is commonly referred to as the modern time, which has persisted for about 10,000 years. The time interval before the last glaciation is known as the Sangamonian Stage.
The climate in central Illinois then averaged about five degrees warmer than the present. Red clay soils formed on the hills around Vandalia during this time, which were buried by loess (wind-blown silt) during the last glacier stage. At the land surface today, a variety of high-quality soils have formed in the loess.
Quoting Jacobs and Lineback, “The glacier deposits of the Vandalia region are of special interest because of the abundant and extensive sand and gravel deposits that have long been an important source of building and road materials.”
“Sand and gravel deposits are relatively small and widely scattered elsewhere in south central Illinois. The whole area of glacier activity is known as the ridged drift of the Kaskaskia basin. The ridges and knolls extend as far southwest as Randolph County and northwest in Christian, Sangamon and Logan Counties.”
Topographical quadrangles of Fayette County along the Kaskaskia River watershed reveal several gravel pits in the immediate area. Some of the pits are still in operation today.
Briefly, the literature indicates that several glaciers made many advances into this region. Ridges of 50 to 100 feet were deposited by meltwater streams in ice-walled channels during stagnation of the glacier that deposited the Vandalia sediments. The results of the glacial deposits created ridged landscapes.
Over time, some of these formations have been given local names. They are know as Thrill Hill, Vandalia Country Club Hill, Hobler Hill and Shoe Factory Hill just to name a few.
The Fayette County Courthouse and Fairlawn Cemetery are also situated on ridges left from glacial meltwater and deposits.
North American Sand & Gravel Company and Vandalia Sand and Gravel pits are located where elongated ridges and knolls have left gravel and sand deposits.
Dean Hills east of Ramsey rising 689 feet above sea level and winding Ridge Road southwest of Vandalia are also formations resulting from the glacial period.
The beauty of the hills and valleys has always been my special interest. The Vandalia area and region is very unique in the geographical features found here.
Economically, the glacial deposits have had a significant impact on Fayette County and the surrounding region. The gravel pits produce materials for sale and provide jobs. Varying soil types result in good agricultural lands for farming. The quality of soils and subsequent vegetation help to produce and maintain good wildlife populations.
Rolling and hilly landscapes are desirable for home site developments, as is evident throughout the area. Vandalia Lake is cradled between some of the ridges and hills. Many features of glacial action resulted in creating an attractive landscape in this locale.
Local folklore has even suggested that an Indian tribe helped name Vandalia. Supposedly, the tribe was called the “Vandalls.” However, this was never substantiated, according to the “Historical Souvenir Of Vandalia Illinois.”
Quoting from this book, “the most reasonable solution to the question is that the location was in the Van of settlements in the state, and because of the hills and dales surrounding it, therefore “Vandalia.” Whatever the reason may be, I hope people in the community find the geographical history of the Vandalia region interesting.
The spring period is here and perhaps now would be a good time to take a drive and enjoy the hills, ridges, and valleys. Mother Nature has certainly worked her magic on an area that could have easily have been as flat as other parts of south central Illinois.
Here in the 1990s, I’m still impressed by the view from Thrill Hill. However, I often look back east from the hill and now daydream a bit about my old high school days.