Highway 11 is now closed between Cochrane and Greenstone because of heavy snowfall that could leave up to 20 cm of snow in some places.
Barriers have been installed to prevent traffic on this important section.
HWY 11 Is closed Both sides of Hearst.In the Northwest, Trans-Canada Highway 17 is closed between Terrace Bay and Marathon due to ice on the roadway.
According to Ontario 511, Highway 101 between Wawa and Chapleau is also closed for an indefinite period.
Earlier Thursday morning, the community of Oliver-Paipoonge west of Thunder Bay was not able to clear its roads properly.
Mayor Lucy Kloosterhuis had to declare a state of emergency, while Wednesday's heavy rain, followed by snowfall, turned roads into ice rinks.
Mayor Kloosterhuis urges residents of her community to stay home until the route is cleared.
The Ontario 511 site showed Thursday morning snow-covered roads over much of the northwestern part of the province and reduced visibility around Thunder Bay and Marathon.
Schools closed
The heavy snow that began Wednesday night ended on Thursday morning with the closure of schools in rural areas and the cancellation of all school transportation in the Thunder Bay area, Hearst Area and Timmins Area!