Here are some excerpts taken from the USRA Final System Plan, July 1975:
"On March 28, 1975 the USRA reevaluated the segment of the line from Vulcan, Ohio (crossing of the TT) MP 300.2 to Ottawa Lake MP 310.0 and found it eligible for inclusion in Conrail. Service to that portion of the line would generate $877,960 in revenue and $669,187 in costs with a resulting contribution of $208,773. Service to the remainder of the line, from MP 310.0 to MP 328.3 would generate $260,177 in revenue and $467,557 would require approximately a tenfold increase in traffic or an 80 percent rate increase over the 1973 levels."
From there things get a bit complicated. PC owned much branchline trackage in mostly agricultural Lenawee County. The state of Michigan didn't want to see all or most of this PC trackage abandoned, so they stepped in and purchased some of it, and tried to convince the DT&I to purchase some, too. Conrail operated some Lenawee County trackage under contract with Michigan until 1978, when new shortline operator Lenawee County Railroad Company was formed.
More from the USRA: "The portion of the Vulcan Old Road branch from MP 328.3 (N&W Crossing) to MP 324.5 (Lenawee Jct) shall be offered for sale to the DT&I. If this offer is not accepted, the line is NOT designated for transfer into Conrail. The portion of the Old Road branch from MP 315.5 (Riga, DT&I Crossing) to MP 324.5 (Lenawee Jct) shall be offered for sale to the DT&I. If this offer is not accepted the line IS designated for transfer into Conrail. If the DT&I DOES NOT acquire the portion of this line from MP 315.5 to MP 324.5, the portion of the line from MP 315.5 to MP 310.0 (Riga to Ottawa Lake) IS designated for transfer to Conrail. If the DT&I DOES acquire the portion of the line from MP 315.5 to MP 324.5, the portion of the line from MP 315.5 (Riga) to MP 310.0 (Ottawa Lake) IS NOT designated for transfer to Conrail. Finally, the portion of the Old Road from MP 300.2 (Vulcan, TT Crossing) to MP 310.0 (Ottawa Lake, Michigan) IS to be transferred to Conrail."
That's probably more detail than you care to know. Again, Michigan didn't want all of the PC branchline trackage in Lenawee County to go away. In the end Conrail ran north of Ottawa Lake to Clinton to serve a large Budd Company facility there. When Budd closed their Clinton factory in 1981, Conrail had no reason to operate beyond Ottawa Lake any longer, and the rail north of Ottawa Lake was pulled, either in late 1981 or 1982. Lenawee County Railrooad Company operated the trackage from Riga to Lenawee Junction to Adrian, and another former PC line from Grosvenor to Morenci, from 1978 until they went out of business in 1990. The Grosvenor-Morenci line was abandoned, and in 1991 the Adrian and Blissfield Railroad began operations between Riga, Lenawee Jct and Adrian. North of Lenawee Junction, following the Conrail abandonment in 1981, a tourist railroad called Southern Michigan Society purchased the line from Lenawee Jct to Clinton. That group has been operating tourist trains between Clinton and Tecumseh, and between Tecumseh south to Raisin Center, since 1985. At Raisin Center the former diamond at the NS crossing was removed as soon as Conrail abandoned the line, so SMRS owns two pieces of unconnected track. Their track from Raisin Center to Lenawee Jct has remained dormant for nearly 30 years, although they do have several pieces of equipment stored there. Recently there was some discussion that the Adrian and Blissfield might buy the SMRS, perhaps for the purpose of rebuilding a connecting track at Raisin Center.
I visited some relatives in that part of Michigan over the holidays, and the route to their house takes me by the Old Road in Ottawa Lake. Still stored on northernmost point of the Toledo-Ottawa Lake line, close to the end of track bumper which is located several hundred feet north of the elevator itself, is the elevator's Alco switcher. Its prime mover failed quite a few years ago and it was pushed to the end of the track, where it still sits. The elevator uses an SW switcher today I believe, although it is difficult to get a glimpse of it as it is kept in a covered area when not in use. The Old Road between Toledo and Ottawa Lake is dormant for most of the year, as the only customer is the grain elevator.