“The westerly migration is clear out beyond the Elwha River (on the Olympic Peninsula), so I think it’s safe to say a 60-mile radius is pretty accurate,” Warren said.

As many as 300,000 Atlantic salmon started escaping from a Cooke Aquaculture salmon farm off Cypress Island, which is about 50 km northeast of Victoria in the San Juan Islands, on Saturday when structures anchoring the facility began to fail in strong tides.

On the Canadian side, however, commercial fishing closures to protect lower-than-expected sockeye salmon returns mean there are few people out fishing to encounter the escaped Atlantics and find out how far north they might have come, said Sonia Strobel, managing director of Skipper Otto’s Community Supported Fishery.