From publisher blurb:
Everyone around Box Elder calls him, “The Breed,” for he is a half-breed. His father was German and his mother was Arapahoe. Despite his mixed heritage, it was through the cattle trade that he found a way to prosper in life in the new world of the white man's progress. Despite the way that he was treated by the other cattle men over the years, he now owns the most enviable spread in the area.
Then the rains stopped. The creeks and streams have all dried up. Even some of the wells have gone dry. A plague straight from the pages of the Bible has fallen on Box Elder. It has become difficult to find enough water for all of the livestock. There is water aplenty in Slakethirst Lake, but it sits in the middle of The Breed's ranch and he is in no mood to share. Some suspect that perhaps there is a different reason other than revenge that causes him to deny the others a drink of his water.
While this adventure is set in the Boot Hell campaign setting, it can easily be used in any sort of Western steampunk or horror roleplaying game. It uses 5th Edition SRD rules as a default.