Katy, a red crawler tractor, belonged to the Highway Department of the City of Geoppolis. She was not used in winter, however, until a huge snow storm snowed in the whole city. Then Katy plowed out everyone.

Every year, the whole town looks forward to the Christmas tree lighting, but this year, a blizzard has struck. The snow starts to fall more and more heavily, and soon, Tractor Mac and his pals are snowed in at the barn. Farmer Bill and Sibley the horse is supposed to be on their way to the center of town with the tree, but when they get stuck in the blizzard and it looks like the ceremony will have to be called off, Tractor Mac saves them and the...

Sibley the horse lives on Stony Meadow Farm and is a hard worker the whole year round. Then Tractor Mac arrives at the farm, and suddenly, everything that Sibley used to do, Tractor Mac does, too. Sibley wonders if there is any room left for him -- but when Farmer Bill and Tractor Mac get stuck in a soggy field, Sibley is the one who comes to their rescue, and Sibley and Tractor Mac learn that there's plenty for both of them to do at the farm.

After seeing a plane flying through the sky, Mac the tractor decides that he wants to fly.

While Farmer Dougal is sleeping, Sheep convinces the other farm animals to take a ride on his tractor and imitate the different noises that it makes.

Tractor Mac is hard at work in the field one day when his engine starts to make a funny noise. It doesn't sound good, and it doesn't feel very good, either. Tractor Mac is scared that he has to take a trip to Dr. Lou at the tractor hospital, but with the help of his animal friends and some other machines who have stopped in for a tune-up, he learns that going to the doctor doesn't have to be scary at all.

When the farmer places a scarecrow in the cornfield, Otis the tractor and the farm animals try to make friends, but the scarecrow remains silent with a sour look on his face throughout the summer and fall.

Otis the tractor is happy to go home and rest after a very busy day of working on the farm and playing with friends.

"A brother and sister explore all the different kinds of tractors there are"--