Geography of Cass County, Illinois

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Cass County, located in central Illinois, is characterized by its diverse geography, agricultural landscapes, and historic communities. From the fertile prairies to the winding rivers, the county’s geography plays a significant role in shaping its economy, ecology, and cultural heritage. In this comprehensive overview, we’ll explore the geography, climate, rivers, lakes, and other notable features of Cass County.


According to Ezinesports, Cass County covers an area of approximately 384 square miles in central Illinois. It is bordered by the Illinois River to the west, Mason County to the north, Menard County to the east, and Morgan County to the south. The county seat is Virginia, while other significant communities include Beardstown, Ashland, and Chandlerville.

The landscape of Cass County is predominantly flat to gently rolling, with fertile prairies and farmland covering much of the area. The county lies within the Central Till Plain region of Illinois, characterized by its rich soils deposited by glaciers during the last Ice Age. Agriculture, particularly the cultivation of corn and soybeans, is the primary land use in the county.


Cass County experiences a humid continental climate, with hot, humid summers and cold, snowy winters. The region’s climate is influenced by its location in the central United States and its proximity to the Great Lakes and Mississippi River.

Summers in Cass County are warm and humid, with average high temperatures ranging from the upper 80s to low 90s Fahrenheit (around 31-34°C). High humidity levels can make the temperature feel even warmer, particularly during heatwaves in July and August. Thunderstorms are common during the summer months, bringing heavy rainfall and occasional severe weather.

Winters in Cass County are cold and snowy, with average high temperatures in the 30s and 40s Fahrenheit (around 0-5°C). Snowfall is frequent, particularly in December and January, with average annual snowfall ranging from 20 to 30 inches (50-75 cm). The region can also experience occasional cold snaps, with temperatures dropping below freezing for extended periods.

Spring and fall are transitional seasons, with gradually changing temperatures and blooming vegetation. These seasons bring mild, pleasant weather, making them ideal times to explore Cass County’s outdoor attractions and cultural events.

Rivers and Lakes

Cass County is home to several rivers, creeks, and lakes, which play important roles in both the region’s ecology and human activities such as recreation, fishing, and agriculture.

The Illinois River forms the western border of Cass County, providing habitat for diverse wildlife and supporting recreational activities such as boating, fishing, and birdwatching. The river is navigable for much of its length, allowing for commercial shipping and transportation of goods.

Other significant rivers in Cass County include the Sangamon River, which flows through the eastern part of the county, and the La Moine River, which joins the Illinois River near Beardstown. These rivers and their tributaries provide habitat for various species of fish, birds, and other wildlife, as well as opportunities for outdoor recreation and scenic beauty.

Cass County also contains several lakes and reservoirs, including Lake Petersburg and Spring Lake, which offer opportunities for fishing, boating, and picnicking. These lakes provide additional recreational opportunities for residents and visitors alike, as well as important habitats for waterfowl and other wildlife.

Natural Attractions

In addition to its rivers and lakes, Cass County boasts several natural attractions that showcase the region’s beauty and biodiversity.

The Jim Edgar Panther Creek State Fish and Wildlife Area, located near Chandlerville, encompasses over 16,000 acres of forests, wetlands, and prairies. The area provides habitat for a variety of wildlife, including white-tailed deer, wild turkeys, and bald eagles, as well as opportunities for hiking, birdwatching, and hunting.

Beardstown Park District, situated along the Illinois River, offers a variety of outdoor recreational opportunities for residents and visitors. The park features picnic areas, playgrounds, walking trails, and sports fields, as well as a marina and boat launch for access to the river.


Cass County, Illinois, offers a diverse array of geographical features, including fertile prairies, winding rivers, and scenic lakes. The region’s humid continental climate, abundant natural resources, and recreational opportunities make it a desirable destination for residents and visitors alike. Whether it’s fishing on the Illinois River, exploring the trails of Jim Edgar Panther Creek State Fish and Wildlife Area, or enjoying a day at the park, Cass County invites visitors to experience the best that central Illinois has to offer.