The People in Yonder — Troy D. Smith

A WESTERN TRAIL BLAZER DIME NOVEL (SHORT STORY):

Two mountain men, Harry and Joe, stand before a strange phenomenon they found on the grassy plains-an aperture, a jagged hole in the sky. Is it an opening into another, evil dimension? The strange opening swirls with wild colors, and there are shadowy, demonic figures inside. One man is frightened, but one is mesmerized. And what does this have to do with the Battle of the Little Big Horn?