When the Venango River Corporation restructured in 1989, they sold the Chicago South Shore & South Bend to the newly organized Illinois & Michigan Railway, which operated it as the west end of its Detroit-Chicago mainline until it too fell into debt in 2017 (but was taken over by the D&H & OSW instead of being allowed to go bankrupt.)
As a Groupe I&M subsidiary it continued to operate as a diesel-powered class 3 railroad, picking up a few branchlines as it went (the ex-N&W line from Michigan City’s waterfront to the vicinity of the Kingsbury Ordnance Plant, which had been partially redeveloped as an industrial park, and the new I&M line from Niles to New Carlisle, which was “sold” to the railroad when Groupe I&M started having cashflow problems and wanted to spread the debt around)
When the D&H merged with Groupe I&M the CSS&SB became a subsidiary of the PV&T, which promptly reelectrified freight operations (except for the southern end of the Kingsbury branch (La Porte to Michigan City was electrified so NICTD could run commuter trains there), which didn’t have nearly enough traffic to justify stringing wire just yet, and had a handful of DL16c’s transferred in to handle freight traffic) and brought in 4 BCC4’s and 4 O’s to handle online traffic, then connected the unused section of the ex-N&W line from the Michigan City shops to the existing power plant branch to build a freight belt to bypass the street trackage in Michigan City (NICTD still wanted to get the old CSS main along 11th St moved to private ROW, and the South Shore was fine with that as long as they could still use it in emergencies and didn’t have to pay for it.)
When the new ownership cleared out the Michigan City yard as part of the freight belt construction project, Russa #801, which had been lingering in the dead line at Michigan City for the past 30 years, ended up being sent to the Musée ferrovaire de Parsons Vale in Saint-Constant, PQ, to stand in for the earlier class D units that went to the Milwaukee Road half a century earlier.
In 2020, the CSS&SB electrification was extended east – energized at 25 kvac – along the I&M all the way to Ypsilanti, with a new branch west of Jackson to connect to the Jackson & Lansing and the Jackson Connecting Railroad.
As of 2023, the CSS&SB’s roster consists of
| number(s) | class | builder | notes |
|---|---|---|---|
| 265-269 | BCC4 | Portland | |
| 803,805-807 | M | Portland | |
| 1238,1239 | J | Portland | ex-M&B #60 & 61, rebuilt to class JS specs |
| 1319-1323 | O | Portland | |
| 1395-1399 | DP4 | ILW | |
| 1405-1407 | K3r | Portland | ex-Amtrak #954-956 |