The Illinois River begins south of
Joliet near
Interstate 55 and heads west through
Morris,
Marseilles,
Ottawa and
La Salle. West of Lasalle, near the Lake DePue Conservation Area (CA), the river begins to head south into
Peoria, then southwest to just below
Beardstown and finally south again emptying into the
Mississippi River at
Grafton.
The river gives rise to a multitude of recreational areas, including Goose Lake Prarie State Natural Area, William G. Stratton State Park, Gebhard Woods State Park, Illini State Park, Buffalo Rock State Park & Effigy Tumili, Starved Rock State Park, Matthiesen State Park and Spring Lake State Park.
