When the gasoline, diesel and electric shovels arrive, it looks like Mary Anne the steam shovel will be sold for junk, unless Mike can think of a really special job!
Katy, a red crawler tractor, can do a lot of things. In the summer she is a bulldozer, in the winter, she turns into a snowplough, waiting for her chance to be useful. Most of the winters, though, the snowfalls are mild and the town doesn't need Katy. But when the big one finally hits the entire community is dependent on one little snowplough.