Walt was worried, however...
Alliteration (w sound)
His father had gone prospecting for quartz
To go searching for valuable ores, such as gold.
What is the climax in the story?
Walt strikes the Irishman in the face with a whip.
...for the creek wound back and forth like a snake...
Simile (like a snake)
The sled was poised perilously on one runner.
Dangerously
At this space they remained, a black speck of motion on the white river-beast.
Metaphor (black speck / river-beast)
They were constantly floundering off the beaten track.
to struggle or stagger helplessly or clumsily
[He] dashed round the bend with a couple of revolver bullets singing after him...
Personification (singing bullets)
The claim was liable to be jumped at any moment because of this delay.
likley to do or be something
In the afternoon, he [Walt] was trailing on their heels...
Idiom (on their heels)
The sled was jumping and plunging and yawing like a boat at sea.