It will be interesting to see if they extend these closures.

Official announcement

Wow, even the undeveloped areas.

3/18/2020 Toronto — Today, Christine Elliott, Deputy Premier and Minister of Health, and Jeff Yurek, Minister of the Environment, Conservation and Parks, issued the following update on Ontario Parks operations in response to COVID-19 developments:

"As COVID-19 continues to quickly evolve, we want to ensure public safety and the well-being of our visitors and staff in Ontario's provincial parks. In order to assist the province with its efforts to keep Ontarians safe during this time, all provincial parks will be closed to the public from March 19, 2020 until April 30, 2020. This includes car camping, backcountry camping, roofed accommodations, day use opportunities and all public buildings.

Current visitors to provincial parks will be required to vacate by March 19, 2020. Any person or group with a reservation for arrival up to April 30, 2020 will automatically be provided a full refund with no penalty.

Ontario Parks continues to monitor the COVID-19 situation carefully. Please visit OntarioParks.com for the most up-to-date information."

With the April 30th date I am still clinging to a thread of hope for an Ontario paddling trip in late May.
The thread is very thin, however.

This is a head-scratcher. How do you close Algonquin, Quetico, Killarney or any back country park?

And for a little bit of context in the absurdity of all of this, the province of Ontario owns and operates all liquor stores (LCBO) in the province...which remain open.

But when you think about it, this virus has the potential to stress the healthcare system dramatically. Ontario's "free" healthcare system is partially funded by the usurious prices charged for wine and spirits. Same for beer but that's another story. About $2.3 billion is transferred annually to the provincial treasury from the LCBO. That's serious money. And folks are stuck at home for the forseeable future with much time and little to do. A bit like Dr. Strangelove's post-apocalyptic mine-shaft idea except instead of breeding prodigiously we shall drink prodigiously.

The park system operates a loss. To digress, the parks in the NW section of the province (including Quetico and Wabakimi) comprise the biggest drain on revenues - considerably offsetting the profitable southern parks and dragging the lot into the red.