The last cowboys - Harry Horse

In this third adventure starring Grandfather and his dog Roo, the search is on for Roo's grandfather, last heard of living in the Wild West.
After starting off in Hollywood, the pair set off to cross America on a Greyhound bus.
But this bus is full of greyhounds, on their way to the Silver Whippet race track and Rabbit World. Things go from bad to worse when they miss the bus due to Roo's rodeo exploits and end up hitching.
The pair end up in One Horse Town where Roo is elected sheriff and then run out of town.
But just as things look really bad - the travellers are trapped in a cave in the snow after following the star buffalo - rescue arrives in the form of Roo's grandfather himself. All ends happily.