It growed a little louder and a little nearer.

And then it struck a plank bridge somewheres, and come acrost it with a clatter.
Then I knowed it wasn't cattle.

Cows and steers don't make that cantering kind of noise as a rule; they trot.

It was hosses crossing that bridge.

And they was quite a lot of 'em.
As they struck the dirt road agin, I hearn a shot.