Painted Ponies — Alan Le May

First published in the US in 1927, now public domain in the US and Canada. A man who has killed in self-defence is hunted across hundreds of miles by a band of vigilantes led by his victim's brother. Ben's troubles began when he killed Lew Cade in self-defense and Abner Cade, Lew's brother, turned a band of trigger-happy vigilantes against him. The grim chase ranged over hundreds of miles, but Ben hung on though the months of privation and peril to return to the Roaring river for a showdown fight.