The fires that are deliberately set to stimulate certain plant growth got a late start this year. That's because the ground was wet and snow covered after the long, harsh winter. Burning typically begins in mid-March and runs through mid-April.
Chris Young is a spokesman for the agency. He says some crews have finished the controlled burns in portions of the state, but are still conducting them in northern Illinois.
Young says there's no set number of acres that needs to be burned this year, but the agency typically burns between 10,000 and 20,000.
The areas that are burned are typically portions of prairies and woodlands.