Oak trees on Pioneer Road.RoundTable photo

Illinois was nicknamed the Prairie State because 60% of its landscape was originally prairie. About 40% was woods. What else could have inspired Dwight Perkins to work so passionately to create the Forest Preserves in northeastern Illinois? Evanston was part of that 40% woodland and has soil suited to the growth of trees.

When the last glacier to cover Chicago retreated to the northeast from whence it came, it left in its wake a large lake that scientists call Glacial Lake Chicago. Eventually, as Lake Chicago receded, its bed, the Chicago lake plain, emerged. With both the lake and the glacier gone, the Evanston landscape was left with old beach ridges where the lake edge had rested: 12,000 years before the present (Gross Point Road), then 10,000 years before the present (Ridge Avenue), and finally 4,000 years before the present (Chicago Avenue).

Between the ridges was low marshland, too wet to support trees but perfect for wet prairie. The North Shore Channel runs through the widest of the marshes. The ridges supported trees, primarily oaks. The marshes were filled with water for maybe half of an average year, making communication difficult between settlers who lived on the ridges.

The first description we have of the Evanston area landscape comes from the Public Land Surveys that divided the land into Townships, Ranges and Sections so it could be purchased by settlers. As surveyors walked each section line, they recorded what they found. In the general vicinity of the area now known as Perkins Woods, known earlier as “the Big Woods,” and part of the first half mile of the section line – near today’s Prairie Avenue – surveyor George Harrison recorded “Land level and wet prairie.”

But continuing north and reaching the quarter-section point, the intersection of what became today’s McDaniel Avenue and Simpson Street, he recorded a bur oak 10 inches in diameter, and a bur oak 12 inches in diameter. On his walk north, he found even more trees. When he reached the intersection of McDaniel Avenue and Central Street, he recorded “Timber Red and White oak, ash, elm, Lynn, bur oak, hickory. Land level and wet.”

Scientists eventually called this area “the swamp morainic forest;” trees could grow if the land was low and wet, but not too wet.
Mr. Harrison’s notes of vegetation on the ridges near Lake Michigan show timber, with marsh in the depressions between.

The next description comes from the Methodist group looking for a location for their university that would serve all of the
Northwest Territory. Harold Williamson and Payson Wild, in “Northwestern University: a History, 1850-1975,” describe how Orrington Lunt and a companion located the spot by accident during a scouting expedition in 1851. Mr. Lunt’s friend wished to visit a friend who lived east of the ridge about where Davis Street is today, in the aptly-named town of Ridgeville.

While waiting for his friend, Mr. Lunt recalls he “took a stroll over to the lake through the wet land, and I well remember walking over logs or planks on a portion of it. … In looking south, it was wet and swampy; looking north, I noticed the large oak forest trees. The thought first struck me that here was where the high and dry ground began. Going through the woods
   to the lake shore and looking north toward today’s Sheridan Road and Lincoln Street], I saw the high, sandy bluff perpendicular as at present. On a beautiful August day, the whole committee regarded the site. “We drove into what is the present campus, and it was just as beautiful as now in its natural condition. We were delighted; some of the brethren threw up their hats. – We had found the place.”

It took another 50 years before scientists and historians took an interest in Evanston’s original landscape, time enough for it to have changed dramatically. Historian J. Seymour Currey, writing about early Evanston in the 1903 Evanston Index, identifies three ridges running through Evanston. Forest Avenue, Hinman Avenue and Ridge Avenue. All were covered with oaks and associated species. He remarked that the oaks had begun to die when the marshes were drained. Oaks do best when their hydrology is stable. Elms from the Big Woods were planted to replace the oaks.

Lillian Simmons wrote her master’s thesis for Northwestern in 1920. “Forest Distribution of the North Ends of the Lake Chicago Beaches” drew upon anecdotes and new scientific studies of ecology. Her study verified that where the soil is rather coarse and well-drained – as on the crests and slopes of the ridge – oaks, especially red oaks, prevailed. She noted that white oaks might have been more predominant, but because of their value for construction, they might have been the first trees logged.

The spacious front lawn of the Harley-Clarke mansion could well have been part of this oak woodland. Whatever happens to the mansion need not influence what happens to the lawn, which at present is certainly not rooted in Evanston history. The grassy sward is a type of landscape developed in 18th-century England and France for wealthy landowners. It does not reflect today’s appreciation for the ecological value of green infrastructure.

 Ideas for a different landscape have included prairie, which would be inappropriate for this literal neck of the woods. Perhaps it is time to think about returning the lawn to Evanston’s roots, to plant oaks plus an understory that would require minimum maintenance and reflect Evanston’s natural history.

Anyone with a stately oak in the yard  may send a photo to share with readers to libbyhill@comcast.net.

Libby Hill is the author of "The Chicago River: a Natural and Unnatural History. She has been writing about birds and trees and Evanston's natural history for the Roundtable since 2004.