Yellowjacket, too--she had never ridden at that terrific speed down hill.

Twice she lost a stirrup and grabbed the saddle horn to save herself from going over his head.
They neared a sharp turn, and it took all her strength to pull her horse to the inside and save him from plunging off down the canyon's side.

The nose of the hill hid for a moment her dad, and in that moment she heard a crash and knew what had happened.

But she could not stop; Yellowjacket had his ears laid back flat on his senseless head, and the bit clamped tight in his teeth.
She heard the crash repeated in diminuendo farther down in the canyon.
There was no longer the rattle of the wagon coming down the trail, the sharp staccato of pounding hoofs..