Bonanza - Caterpillar Tracks
I seen this in "BONANZA", Season.3., episode 14,intitled GABRIELLE. About halfway into the episode, Gabrielle, a young blind girl, is walking with her friend through snow to her grandfathers cabin in the hills. As they are walking along a cleared bit of ground, you can see the slush on the ground and in the slush are caterpillar tractor tracks! I don't think there were any caterpiller tractors around in the 1800's.