From its yard on the east bank of the Mississippi River at River Yard (MP 0.0), the Alton & Southern heads east-northeast, single track, Yard Limits, maximum speed 10 mph, past a line trailing in from the southwest, from American Milling and Fox Terminal, also on the east bank of the river, south of the yard, a former flat crossing with east and west quadrant connectors with the erstwhile former Mobile & Ohio, a flat crossing with the TRRA Eads Conologue District at Conologue (MP 0.8), where Two Main Tracks start, still in Yard Limits, industrial tracks trailing in on the south side, two separate sets of industrial tracks heading away on the north side, a location where there was once a connector to an ertswhile interurban that also once made a flat crossing at the junction with the TRRA Illinois Transfer District at Wiggins (MP 1.8), where the A&S used to continue straight ahead on its own track to Valley Junction, and there is still a flat crossing with the TRRA line and a stub of A&S track beyond, but the main now takes the south quadrant connector onto the TRRA line east to its junction with the former MoPac/Cotton Belt joint line coming from the south-southwest, and turns north-northeast, past two ertswhile connectors on the west side, two flat crossings with former Illinois Central lines coming west from their East St. Louis Yard, a connector trailing in on the east side from that yard, and the TRRA Illinois Transfer District continuing ahead where the A&S once made a flat crossing but now just curves away east-northeast at Valley Junction (MP 2.2).