Barking Like Dogs
"We've seen the wildest things! Folks down on all fours barking like dogs!" - Liza, "The Revival"
In this simile, Liza is attempting to emphasize the crazy things she and her friend Fannie have seen while staying at the Cane Ridge Revival in Kentucky. This particular bit of figurative language does exactly that; it emphasizes the primal parts of men's minds that are affected by charismatic religion, although whether this specific circumstance genuinely affects a man's soul with the Holy Spirit or merely encourages him to degrade himself is difficult to determine.
The Spring Chicken
"Probably just exhaustion. Skinny's no spring chicken." - Willy, "Hundreds of Feet Below Daylight"
Skinny, an older prospector working in the mines, has collapsed, and Willy thinks it's probably just exhaustion because of Skinny's age. To emphasize this, he uses the metaphor of a "spring chicken," meaning a chicken in spring who has just hatched, accentuating that Skinny is, in fact, not one of these, a common expression of understatement.
Gone Faster
"This town's run out of luck! I get my money and I'm gone faster..." - Ricks, "Hundreds of Feet Below Daylight"
This sentence actually contains an unfinished simile, but it's one that completes itself by proxy of suggestion. Ricks is about to compare his speed in leaving the town to something, but he's cut off by someone else. This unfinished simile accentuates and foreshadows the fact that Ricks will never actually get his money, meaning he will never have to leave faster than anything at all.
Dumb Like a Child
"Their spirits have struck Skinny dumb like a child." - Unnamed miner, "Hundreds of Feet Below Daylight"
Skinny has physically recovered, but it seems he's had a mental breakdown, as he's wandering the town and enigmatically moaning a single name: "Iris!" The miners are gossiping about the story, saying that a cave-in killed Skinny's former workers, and their spirits are now haunting him. The simile emphasizes Skinny's current mental condition, which is incongruous with his advanced age.
Gutted Like a Fish
"Then one of Iris's Joes gut her open like a fish." - Ricks, "Hundreds of Feet Below Daylight"
In this scene, the miners continue to discuss Skinny's life, and they 'remember' that Iris is his daughter whom he forced into prostitution to make money until one of her "Joes" (male clients) killed her by slicing her open. This horrible simile emphasizes the brutal and degrading method in which Iris's client allegedly killed her, and it also speaks to the moral depravity of the men discussing the matter.
