I don't have much info regarding the Tier.
Things were very busy or so it seemed right to the end and into very early Conrail in that area.
The D&H RS-3m's rebuilt by M-K including the Red / White / Blue 508 were delievered very close to the end into Binghamton and the EL Bi-Centennials were frequent. EL also ran an inspection train with E-8 #833 if I recall correctly and some business cars. At one time someone had a scene of it in the Tier (near Erwins I think) made into a post card that may still be found somewhere.
Up the Utica side we lost NE97-74 which last ran under that symbol on March 30, the train on the 31st being an Extra Utica to Sherburne with the 1274 & 1283. The Norwich and Sherburne locals ran as usual and lasted to the last day of CR operation before NYSW.
On March 27, 1976 there were four or five detours run south "fleet style" due to a wreck on the PC near Rome. Big time railroading that day as trains went south from Utica to Chenango Forks, got pulled by with a pull by engine up from Binghamton and then went north on the Syracuse Branch and back to the PC mainline.
Everyone had thought for a while that the EL lines would go into MARC-EL and be operated by Chessie. The unions turned it down but alot of the guys in rank and file thought it would have been a good thing.
Out west Marion to Chicago alot of guys made their last runs. Guys went up to the PC lines as the seniority rosters were dovetailed.
It was a sad time, alot changed for many people and no one really knew what to expect from Conrail. I remember driving through Hornell about 1978 and seeing dozens of houses up for sale as the shops were closed.
Basically I remember alot of uncertainty in the minds of the railroaders I spoke with back then and for a long time after as EL operations gradually closed down and morphed into what we know today under NS. One rumor that persisted into at least Fall 1978 was that the EL might pull out of Conrail and reclaim their railroad. As far as I know there was no basis other than perhaps some stipulation that EL lines would not be torn up for a year or some such. It was hard to separate reality from rumor (still is in today's railroad world). One thing was certain whether you were a LV guy, PC, EL or CNJ or whomever ... things would never be the same again and the game was changing. Alot of speculation on what color the engines would be too before they introduced the blue GP40 out of Collinwood.