I'm looking hard for the rationale for proposed closure.
From the Parks Canada site:
Parks Canada is committed to protecting natural and cultural resources while providing high-quality and meaningful experiences to visitors. ...
Throughout the pandemic in 2020 and 2021, vehicle access on the eastern half of the Bow Valley Parkway was restricted. This interim measure was taken to help support physical distancing requirements at Johnston Canyon, while allowing space for outdoor recreation. The change resulted in an enhanced cycling opportunity on a scenic, well-maintained roadway with minimal vehicle traffic.
It sounds as though local sentiment -- an important factor -- is weighted heavily. There is very little in this statement on actual mitigation of impacts on "natural and cultural resources." Johnston Canyon can be accessed from the western end.
I would be happy to see more animals along the proposed closure and to encounter fewer cars, even if doing so required some auto-free workarounds for me. I assume the animal populations (including a resident wolf pack?) would only be happier, but I'd be interested to know whether Parks undertook studies of reduced impacts on natural and cultural resources or whether that is just boilerplate language, a reiteration of mission.
Adding here some further info I found elsewhere on Parks Canada site, regarding overnight closure in spring:
March 1 to June 25, 8 p.m. to 8 a.m. All activities To give the animals the space they need to thrive during the spring; at crucial times of the day and year
Perhaps the proposed further closures can be read as an extension of this policy and rationale.
Edit to add: I am unsure whether Bow Valley Parkway is part of the Y2Y Bow Valley section; I think technically not.
Nonetheless, possibly of interest:
The importance of wildlife corridors in the Bow Valley
One such corridor in the Yellowstone-to-Yukon region is in Albertaís Bow Valley. This area, just outside Banff National Park, is one of the four most important east-west connectors in the entire 2,000-mile (3,200-kilometer) length of the region, and one of two such valleys in Alberta.
(Y2Y recommends limiting cycling in wildlife corridors, as mentioned in the linked article.)