STORY 9: Crooked Creek

Crooked Creek

The Flowing Beauty of the Palos-Sag Valley

Crooked Creek is a beautiful, winding tributary of the Chicago River system and is home to many fish species including largemouth bass, bluegill, and pumpkinseed.  The Crooked Creek watershed is within the Palos-Sag Valley region of the Forest Preserves of Cook County.

Listen below to an interview with Marla Garrison, a renowned dragonfly and damselfly expert.



The creek flows into the Saganashkee Slough which then drains into the Cal-Sag Channel which connects the Little Calumet River to the Chicago Sanitary and Ship Canal. Crooked Creek traverses under roads and through lush wooded areas of several forest preserves including Country Lane Woods, Cranberry Slough, and Pioneer Woods.

Listen below to an interview with high school teacher Greta Kringle who successfully uses the Chicago River system as a teaching tool.



Natural History of the Palos-Sag Valley

Ice-age glaciers sculpted the landscape of Mt. Forest Island, a geologic name for the land between the Des Plaines River Valley and the Sag Valley. Periods of glacial retreat subsequently created Glacial Lake Chicago; of which its shorelines reached to the present day area of Moraine Valley Community College in Palos Hills, Illinois.

In the Palos region there are almost 100 lakes, ponds and sloughs nestled within hilly woodlands. Seasonal change adds beautiful dimensions to year-round experiences. From Palos Fen in the east to Red Gate Woods in the west, and bounded by the Des Plaines River and Cal-Sag Valley, the Palos area harbors a wealth of historic and natural wonders including the I & M Canal, which connected Chicago with the developing west by trade, and the original site of Argonne Labs, which housed the world’s first nuclear reactor during World War II.

Dan McMahon Woods and the Palos Fen are home to rare alkaline fen ecosystems. Scattered between ravine forests and upland woodlands are marshes and ponds teeming with frogs, birds and other wildlife. Prairie remnants in this predominantly wooded region are small delights, especially in full, late summer bloom. A brochure from the Forest Preserves of Cook County detailing the Palos region is available for download here.

“Glaciers left behind forested ravines, fresh water springs, and fertile farmland which became home to the Potawatomi and other Native American tribes before the French explorers passed through the Palos area,” according to “Images of America: Palos Park” by Jeannine Kacmar. “Ruins of French earthworks were found on the Theodore Lucas farm and French coins and Native American pottery pieces were found on other farms in the area.”

Palos Preserves

At 15,000 acres, the Palos Preserves in southwest Cook County are the largest concentration of preserved land in the Forest Preserves. They are home to oak woodlands, oak savanna, emergent wetlands, and sedge meadows. Thanks to more than three decades of habitat restoration, they also hold some of the highest-quality natural areas in the county. Trails connect many popular sites, such as the Little Red Schoolhouse Nature Center, Saganashkee Slough, and Maple Lake which is home to a mountain bike staging area that provides access to almost 40 miles of unpaved trails. The Palos Preserves are home to an extensive mixed-use trail system, including the paved Cal-Sag Trail, which cross many of these preserve to the south and the paved Centennial Trail/John Husar I&M Canal Trail system to the north. The majority of the Palos Preserves are in Palos Township which contains all or a portion of the following municipalities within its borders: Bridgeview, Hickory Hills, Orland Park, Palos Heights, Palos Park, Willow Spring and Worth

See the Stars: Palos Preserves is the World’s Largest Urban Night Sky Place

In 2021, the Palos Preserves was designated as the largest Urban Night Sky Place in the world by the International Dark-Sky Association (IDA). As an Urban Night Sky Place, the Palos Preserves houses only four buildings, and as a result of the low use of artificial lighting, satellite radiance data show that the Palos Preserves emits nearly 1,000 times less light than downtown Chicago. The Adler Planetarium of Chicago measured about four times more stars that are visible in the night sky over the site than in the City of Chicago. Watch a CBS Chicago news story about this unique designation here.

Landscape Scale and Riparian Restoration

Since 2018, Friends of the Chicago River has partnered with the Forest Preserves of Cook County (FPCC) on a major land restoration project to significantly enhance habitat in the Crooked Creek watershed. As of 2021, more than 425 acres have been restored including miles of riparian area along the headwaters of the creek. In 2014, the FPCC identified this Palos-Sag Valley area of forest preserves as one of its highest priorities for conservation and ecological restoration due to its size, connectivity, high percentage of remnant natural areas, and presence of species of concern.

Funded by the National Fish and Wildlife Foundation Chi-Cal Rivers Fund, this large-scale restoration project is improving habitat through invasive species control. Target species for removal include non-native honeysuckle, barberry, and multiflora rose. With the subsequent return of native plant species, the project increases high-quality habitat and improves stormwater infiltration. By slowing rainwater into Crooked Creek it also improves adjacent habitat for the endangered Hine's emerald dragonfly by limiting water level fluctuations during flash storm events. This restoration will lead to more than 3 million gallons of additional stormwater infiltrated into the landscape during each one-inch-per-one-hour rain event.

Much of the large-scale invasive species control is done while the ground is frozen so machinery running across the land, and crews working in the area, don't compact or damage the soil. And during the cold months many wildlife species are less active, reducing the impact on them.