Illinois State Route 99 is the main north-south highway in Broan County. This connects Mt. Sterling to Jacksonville, via Illinois State Route 104. IL St Rt 99 passes through the following towns in Brown County. Versailles Hersman Mt Sterling
IL St Rt 99 is multi-plexed in Brown County. U.S. Rt. 24, at Mt. Sterling.
IL St Rt 99 intersects the following highways in Brown County. Illinois State Route 107, at Mt Sterling.
