It happened about 170 miles southwest of Chicago in Moline.
Witnesses called for help when they saw Ashley Waeyaert, 26, crash through the ice about 9 p.m. Wednesday.
The firefighters used an inflatable raft to reach Waeyaert and bring her back to shore. She is now recuperating.
Waeyaert told her rescuers she had gone out onto the river to ice skate.