The incident happened around 5:30 p.m. on northbound Illinois 145 near the Bear Branch Campground, just north of Eddyville.
According to officials, a vehicle hit a woman who was riding a horse along the roadway. She sustained serious but non-life-threatening injuries and was airlifted to a nearby hospital.
A group later arrived to care for the horse, though its condition has not yet been released.
The investigation remains ongoing, and no additional details have been provided.
