^Looking west from Illinois 130 in the heart of Olney, March 2023.
Like most other Illinois state highways numbered in the 200's, Illinois Route 250 runs on former alignments of the route numbered 200 fewer than it, US Route 50. Illinois Route 250 occupies not one but two former alignments of US Route 50, joined by a concurrency with the current US Route 50. The first of such former alignments is on the north side of US Route 50 from Noble to Olney. The second former alignment occupied by Illinois Route 250 is farther east, and parallels US Route 50 to the south from Sumner to Lawrenceville.
Illinois 250 starts at US Route 50 and splits from that route heading east into Noble...
After following an old alignment of US Route 50 into Olney, Illinois 250 joins Illinois 130 south...
At Sumner, Illinois 250 splits south to another former alignment of US Route 50 that carries it eastward...
Illinois 250 ends at Business US50 on the west side of Lawrenceville. To access Illinois 1 or get back to the US Route 50 mainline eastward, you can continue east on Business US50.