Yes, they caused traffic jams, but I think these were stoppages visitors did not mind.
Several calves clung close to their mommas as they crossed the highway.
Watch this video I took posted on Youtube.
With a male bison weighing close to 2,000 pounds and a female at half that weight, it got a little scary as two bisons started "headbutting" next to our car. We quickly maneuvered out of there as soon as we could.
All the previous photos on this post were taken inside our car except for this one where a bison wandered into our cabin area during a snowstorm.
I ran out as quickly as I could to take a picture.