Those tire tracks were also a week old and it had snowed for two more days after they were made. I'm surprised they could be seen.
The owner of Black Bar Lodge set they were recent tracks and had been covered with recent snow. He could still see the indents. Remember they were driving in heavy snow at the time and it continued to snow.
I think in that type of environment it would be very easy to see even with large amounts of snow...you will still have the original indentations that would be covered and would dip down.
These guys can spot bear tracks and foot prints from helicopters I think tire tracks would be much easier to see while on the ground.