Two interesting ways symbolism illustrates the themes of Karen Russell’s “The Prospectors" (2015) is through the motifs of color and of flight and descent.

Russell’s imagery in the story is rich with color—whether it be through the description of Clara’s mother, Mrs. Finisterre, “cubing green and orange melon” during cocktail hour or the “black” Atlantic rippling emptily through the eyeglasses of Mr. Finisterre, Clara’s father. The use of color amplifies the story’s lush, baroque tone and is also entwined with its theme of the consequence of chasing empty materialism. The colorful worlds which Clara, and especially Aubby, desire to inhabit are all-glitter, all-glamour, and ultimately all-surface.

Interestingly, Aubby’s name is short for Aubergine, the “French name for eggplant,” evoking the vegetable’s smooth, purple glossiness. Thus, it is no coincidence that Aubby, the story’s narrator, is obsessed with the appearance of things. When Clara, her best friend, shows up with her arms covered with “pansy-blue” bruises, Aubby fixates on the surface of the injuries, observing the beauty of the color, and never delving into its sinister cause. Aubby’s covering the bruises with a “thin” cloth is symbolic of her unwillingness to view her friend as a complex creature with depth.

Further, prospecting is a recurrent motif in the Depression-era story, so it is no wonder that the color gold pops up frequently and significantly in the text. Gold is typically associated with wealth, royalty, and purity, and Clara and Aubby, who get by through stealing shiny and expensive items from hotels and parties, are attracted both literally and figuratively to its lure. The grand opening night at the hilltop Evergreen Lodge represents their rise into a field of satisfying gold and green. However, the dark trappings of Clara and Aubby’s desire are revealed when they land up at a haunted palace instead, the ghostly twin of the Evergreen lodge:

It was the failed original, crushed by an avalanche two years earlier, the graveyard of twenty-six workers from Company 609 of the Oregon Civilian Conservation Corps.

Significantly, Aubby realizes the men at this haunted lodge are all dead when she notices their amber-hued eyes.

Were all of the boys’ eyes this same hue? Trying to stay calm, I gripped Clara’s hand and spun her around like a weathervane: gold, gold, gold, gold.

Thus, the color symbolism takes on an ominous turn, revealing that the pursuit of mere materialism has led Aubby and Clara to dark places. Since their trip so far has been driven by Aubby, it is befitting that Clara’s new-found agency show the girls a way out of their predicament. During their revelries with the dead, Clara gets a nosebleed, the vivid blood symbolizing both courage and life. The next dawn, it is Clara who saves the day when she breaks the night’s spell and reminds the men in a voice “red” with life that they are dead.

Gloriously, her speech gurgling with saliva and blood and everything wet, everything living, she began to howl at them, the dead ones. She foamed red, my best friend, forming the words we had been stifling all night, the spell-bursting ones:

“It’s done, gentlemen. It’s over. Your song ended. You are news font; you are characters. I could read you each your own obituary. None of this—”

Clara's red voice symbolizes the victory of her female self over the threat represented by the men's sexuality, as well as of her true, lasting friendship for Aubby over Aubby's more opportunistic love.

Finally, the twin symbolism of flight and descent can be said to be tied up with the story’s schema of abrupt twists and reversals, as well as the lessons in store for Aubby's character. The story opens with the striking image of chairlifts “floating” 40-feet above Aubby and Clara’s heads, promising them an ascent or flight out of their current predicament. Aubby wants to escape into financial security, while Clara might want to flee from her possibly abusive family. However, the physical ascent into the rarefied mountain air is accompanied by a symbolic descent into a nightmare, or purgatory, where Clara and Aubby rise to find themselves in a haunted lodge.

Fittingly, when the young women manage to escape their nightmare, it is through descending to level, solid ground, albeit after they have prospected a real, living bird, "rich with solar color." The golden songbird symbolizes the girls seizing back their reality, as well as the agency of Clara, who has so far been shown as manipulated by Aubby. It is Clara who lifts the “yellow bird in her lap,” performing their biggest heist together. Thus, the bird can symbolize Clara’s flight into a more empowered way of being, and Aubby's self-awareness of her own shortcomings as a friend.

Prospecting

Aubby and Clara, the main characters of this short story, see themselves as "prospectors." They both grew up with stories of the gold rush in North America told to them by their fathers. Aubby's father killed himself as a result of gambling on dog-racing; Clara's father owned and ran a hotel whose business stemmed from capitalizing on a local myth about a cryptozoic creature living in the water nearby.

So both men sought to make their fortune from figurative sources—not from selling their physical labour like the CCC workers or mining gold but from knowledge and luck. This mirrors the experience of a prospector: these men made their money from lucky finds, from "magic metal . . . a hundred grand richer in a single hour." These girls are making their money and fortune off their social labour: being used by men as "gloating mirrors."

Parties

It is significant that Clara and Aubby happen upon a lavish party of dead workers. The party is a symbol for the failing fortunes of the men who were trapped, and it is also a reflection of the girls' fading fortunes as social prospectors. Usually, the girls would leave parties with Clara's "magic satchel that seemed to expand with our greed" full of stolen goods.

Once winter hit, however, their "mining prospects dimmed considerably." So the dead workers' party ending—as well as the men being re-buried under their avalanche—is an ominous sign that perhaps these girls' parties will soon come to an end. This is reflected again in that they can only steal the golden bird, who then flies away. Perhaps the girls' freedom from the social labour of working these parties will be worth the loss of stolen goods.

I have linked to an interview with the author about this story. This may give you further insight into the story's themes and symbolism.