"'It'll be dark by the time we get out of the pass,' I said to Davies..."
"'Snow too,' He said. We didn't say anything more..."
"He was thick with the same feeling of mortality I had, I guess."
This passage implies that the storm will around the time the posse reaches their destination. This directly correlates the storm to the hanging of the three "rustlers."
Clark uses weather
to indicate that the situation is growing
The spring feeling, warm when it was still... was gone. Even right out in the sun it was pretty cold now." (pg. 41)
This piece of text describes the weather after the people of Bridger's Wells decide to form the posse. This hints that something grave is about to happen.
The sky... was coming on to storm ... it was mostly shadow, with gleams of sunlight breaking through." (pg. 57)
This description comes right after it becomes apparent that neither Osgood nor Davies can convince the posse to wait. The situation is escalating rapidly.
"... there was a storm coming on, you could feel that definately now." (pg. 97)
This description occurs right after Tetley arrives. He is the catalyst in the formation of the posse.
Foreshadowing via Dialog
Clark utlizes what characters say to foreshadow their later actions.
"If we go and hang two or three men," he [Davies] finished, "without doing what the law says, forming a posse and bringing the men in for a trial, then by the same law, we're... due to be hanged ourselves."
In this passage, Davies predicts what happens in the rest of the book, and with suprising accuracy.
"'Cold wind," I began.
Then, he [Gerald] said, "It's more than wind," and stared ahead of him again.
This example shows that Gerald knows that what the posse is doing is wrong.
This is an indication towards his later dissention towards the hanging of the three so-called "rustlers."
"But I know this," he said, "if we get those men and hang them, I'll kill myself. I'll hang myself.
This quote proves that Gerald will not take the hangings lightly, and that he will likely be haunted by them.
Foreshadowing via Action
"Gil... returned the sombrero, the way he did when he knew something was going to happen." (pg.3)
This implies that Gil intuitively thinks something is going to occur, and, this being a book, it probably will.
Clark uses character's actions to foreshadow both their later actions and the other events of the book.
"...we caught the the sound of a running horse... 'Someone's in a hell of a hurry,' Gil said." (pg. 27)
This sudden appearance of a rider can only mean that something has happened, as no non-inhabitant of Bridger's Wells goes there for no reason.