Illinois State Route 177 runs east-west from Belleville across East-Central St. Clair County. This is one of the main routes connecting Scott Air Force Base to Belleville. IL St Rt 177 passes through the following towns in St. Clair County. Mascoutah
Belleville
IL St Rt 177 is multi-plexed in St. Clair County. Illinois State Route 158, from near Scott A.F.B. to Belleville.
IL St Rt 177 intersects the following highways in St. Clair County. Illinois State Route 4, at Mascoutah.
WB IL St Rt 177 east of Mascoutah. A junction marker on SB IL St Rt 4. EB IL St Rt 177 near Market in Mascoutah. EB IL St Rt 177 near Railroad Street in Mascoutah. EB IL St Rt 177 near 2nd Street in Mascoutah, EB IL St Rt 177 in Mascoutah. EB IL St Rt 158/177 east of Belleville. A guide sign on EB IL St Rt 13/15. A junction marker on SB Greenmount Road. A guide marker on NB Greenmont Road. EB IL St Rt 158/177 in Belleville. EB IL St Rt 158/177 at Mascoutah Ave in Belleville. The western end in Belleville. The western end marker.
