LaSalle County, Illinois in the context of Putnam County, Illinois

Starved Rock State Park is a state park in the U.S. state of Illinois, characterized by the many canyons within its 2,630 acres (1,064 ha). Located just southeast of the village of Utica, in Deer Park Township, LaSalle County, Illinois, along the south bank of the Illinois River, the park hosts over two million visitors annually, the most for any Illinois state park.

A flood from a melting glacier, known as the Kankakee Torrent, which took place approximately 14,000–19,000 years ago led to the topography of the site and its exposed rock canyons. Diverse forest plant life exists in the park and the area supports several wild animal species. Of particular interest has been sport fishing species.

La Salle or LaSalle is a city in LaSalle County, Illinois, United States, located at the intersection of Interstates 39 and 80. It is part of the Ottawa, IL Micropolitan Statistical Area. Originally platted in 1837 over one square mile (2.6 square kilometers), the city's boundaries have grown to 12 sq mi (31 km). Named in honor of 17th century Illinois valley explorer, the Sieur de La Salle, city boundaries extend from the Illinois River and Illinois and Michigan Canal to a mile north of Interstate 80 and from the city of Peru on the west to the village of North Utica on the east. Starved Rock State Park is located approximately 5 mi (8 km) to the east. The population was 9,582 as of the 2020 census, down from 9,609 at the 2010 census. LaSalle and its twin city, Peru, make up the core of the Illinois Valley. Due to their combined dominance of the zinc processing industry in the early 1900s, they were collectively nicknamed "Zinc City."

Peru is a city in LaSalle and Bureau counties, Illinois, United States. The population was 9,896 at the 2020 census, down from 10,295 at the 2010 census. It is part of the Ottawa, IL Micropolitan Statistical Area. Peru and its twin city, LaSalle, make up the core of Illinois Valley.

North Utica, often known as Utica, is a village in Utica Township, LaSalle County, Illinois. The population was 1,323 at the 2020 census. It is part of the Ottawa Micropolitan Statistical Area.

While North Utica is the proper name for the city, advertising on nearby Interstates 80 and 39 refers to the village by its original name, Utica. In addition, people who live in the area, official Interstate signage, and signs indicating the city limits all refer to the town as Utica.

Deer Park Township is located in LaSalle County, Illinois. As of the 2010 census, its population was 492 and it contained 217 housing units.