In 2004, the Société des chemins de fer du Québec started slowly winding down its operations, and the LT&L made irrestistable offers for subsidiaries Ottawa Central and, in 2007, the Chemin de fer Charlevois (the rest of the SCFQ’s subsidiaries ended up back in the hands of the Canadien National, which the Parsons Vale board still regrets.) The OC was in fairly sad shape, so the new management needed to shovel a lot of money into it to fix up the track (as well as purchasing the ex-CP line from Mattawa to Armprior when the Ottawa Valley Railway abandoned it) but by 2015 the railway was again making enough money to pay for itself.
As purchased, the OC used the ex-CN Beachburg subdivision to connect Armprior to Pembroke, but when Bristol Mine stopped shipping by rail in 2014 the west end of the Beachburg sub was abandoned (and lifted soon thereafter; the Pembroke end connected to the line to Mattawa by a fairly curvy connecting line, and the bridge just east of Pembroke where the Beachburg subdivision crossed over the ex-CP line was too low to string overhead wire under – even in 2014, the OC’s corporate masters were thinking about electrification! – so it had to go.)
All of the locomotives it owned prior to the merger are still operating, most still in their original goth black paint, and many of the Parsons Vale’s big 6-axle centuries were transferred to the OC as part of the LT&L/CP transcontinental power pool.
In late 2024, the Algoma Southern, Huron Central, and Ottawa Valley railways were transferred to OC control to simplify traffic flows from (the edge of) Lake Superior to Montréal (These railways maintain their identities, but are all dispatched as if they were part of the Ottawa Central,) and then in 2025 the now combined OC system started putting 25kvac wire up on the line from Ottawa to Sudbury as traffic levels started going up in response to increased container traffic between Vancouver, BC (Canadian Pacific haulage rights; CP has haulage rights over the Parsons Vale system to access the east coast, so there’s a lot of container traffic along this line) and the east coast intermodal terminals in Sydney, St John, and Boston.