Richard Payne, 34, of Kinsman, as well as the two juveniles were treated and released from Morris Hospital, according to Seneca Police Chief Ray Meglan.
"As of right now charges are pending until the investigation is complete," Meglan said.
Courtney Sherman was airlifted to Advocate Good Samaritan Hospital in Downers Grove, where her condition was not known.
Meglan said an EMT who was in the area was the first to the scene of the accident.
"She was coming down the road when the accident occurred and was in the scene within minutes," Meglan said.
Although Seneca's fire department is volunteer, its ambulance service is 24-7, Meglan said.
The EMT did not witness the accident, but another person did.
"The witness said (Sherman) was southbound, (Payne) was northbound and she attempted to pass a vehicle right in the middle of the hill, which is marked no-passing zone," Meglan said.
The semi tried to swerve to avoid the accident, but was unsuccessful.
The semi involved in the crash was not an oridinary-sized semi.
"It was an oversized load; they transport these parking garage concrete panels," Meglan said. "They are wide loads and they come out of Marsailles."
Route 6 was shut down for more than 6 hours
"I got out there a little after 9 a.m. and it never opened up until around 4 p.m.," Meglan said.
An adult female was taken to the hospital Saturday afternoon by helicopter following a two-vehicle crash at Route 6 and Bluff Road in Seneca. Three additional patients, including two children from the SUV and the semi driver were taken to the hospital by land.
Seneca Police Chief Ray Neglan was on scene at the crash and said the vehicle driven by the woman, an SUV, was trying to pass another car and collided with the semi head-on.
The area of Route 6 and Bluff Road in Seneca is a blind curve and is a dangerous area where fatal crashes have taken place in the past.
The crash shut down Route 6 between Seneca and Morris for more than 6 hours.
Patch will update this story as more information is available.
Todd Sherman (no relation), Northern Illinois FireGround Photos contributed to this report.
A correction has been made to this story.