In 1996, the Ottawa Valley Railway took over operations on the Canadian Pacific’s former secondary main line between Smiths Falls and Sudbury under a 20-year lease. If I recall correctly, the OVR’s traffic was largely between Témiscaming and Sudbury; traffic between Mattawa and Smiths Falls was almost entirely CPR bridge traffic, taking a short cut between Montréal and Sudbury rather than taking the long way through Toronto along their main line.
With the recession, rail traffic is down, and the CPR has consolidated all of its trains along its mainline. There hasn’t been any bridge traffic along the OVR in months (I noticed something was up in Renfrew last weekend, when I saw that the tracks were completely unplowed). And indeed, something was up: RailAmerica, the OVR’s parent company, has filed for early termination of its lease on the line. Up and down the line in the Ottawa Valley, communities are freaking out about the possibility of losing their rail line: see the local media coverage in Sudbury, North Renfrew, Pembroke, Arnprior, West Carleton and Smiths Falls. From what I can tell, traffic between Témiscaming and Sudbury will continue, at least for now, but the CPR is now deciding whether to restore traffic on the line between Pembroke and Smiths Falls.
CN tore up its competing track between North Bay and Pembroke years ago; if this line is abandoned, the only track remaining in the Ottawa Valley will be the CN line (formerly the Ottawa Central) between Pembroke and Ottawa, which runs through Pontiac County — and these articles make passing reference to its potential demise (though I haven’t been able to track that down online).
Having said that, the OVR has had no local traffic between Mattawa and Smiths Falls, so — as is often the case when rail lines face abandonment — the impact is more potential than actual. Doesn’t stop local politicians from fretting.