Skip to main content

Possible online services disruption due to Internet related outage

A worldwide technology outage is causing disruption to some State of Illinois online systems.  We are aware of this issue and are diligently working on restoration.

Attention hunters: Visit our FAQ page for information about the use of centerfire, single-shot rifles for deer hunting in Illinois. 

Governor JB Pritzker Illinois.gov Contact IDNR DNR A to Z

Big Tree Programs

Winners of the National Big Tree Program at American Forests by American Forests; 3:23 minutes; Discusses the 700 national champion trees designated through the National Big Tree Program administered by American Forests.    


American Forests Big Tree Measuring Workshop Part 1: Crown Spread  by American Forests; 55:16 minutes; Crown spread is often the first sign of a tree's size. This webinar will cover the two-diameter method, spoke method and common obstacles when measuring crown spread.


American Forests Big Tree Measuring Workshop Part 2: Circumference by American Forests; 1:20:53 minutes; In Forestry, the girth of a tree is measured as diameter breast height (DBH), or 4.5 feet above ground level. This webinar will teach you how to measure the girth of a tree on a flat surface, a tree on sloping ground and a tree that leans. 


American Forests Big Tree Measuring Workshop Part 3: Height by American Forests; 1:02:05 minutes; National champion trees may be 30 feet tall or 300 feet tall. From the red maple in your backyard to the eastern white pine in an old-growth forest, this webinar will show you the most effective techniques to accurately measure the height of trees for all skill levels.