[brudgers]

The bison herd of Lamar Valley in Yellowstone is regularly on the road particularly around sunset. It's an amazing traffic jam.

Stay in your car of course.

[dboreham]

Accessible in winter, readers should note. (Most of Yellowstone can not be accessed by road in the winter).

[brudgers]

Right. It’s kept open in winter because it is the only access to Cooke City.

Wyoming 296 (Chief Joseph Highway) gets closed at the west end of Sunlight Basin.

[ethbr1]

During the winter, I believe there is snowmobile access, either guided or unguided (pass-limited-per-day): https://www.nps.gov/yell/planyourvisit/snowmobiles-snowcoach...