How does John Steinback present and use settings in Of Mice and Men?

In Steinbeck's marvelous novella, Of Mice and
Men, the author employs setting to express his Naturalistic and Socialistic
motifs. 

Salinas
River

Beginning and ending with the solitary
path to the sandy banks of the river, Salinas (which means
fortress), with a green (which connotes peace) pool in a clearing, Steinbeck
creates a sort of Garden of Eden, halcyon in its appearance. There, the two friends
share unabashedly their feelings as they are alone and the need to dissemble is not
necessary as it is once they arrive at the bunkhouse. Outside Soledad, which means
solitary suggesting the aloneness of the men, they revel in their
fraternity.

But, like the Garden of Eden, evil lurks as in
the final scene in which Lennie returns to the river seeking sanctuary, a snake sidles
past him, an obvious symbol of the Eden's evil and the end of Lennie and dream for the
two friends. Yet, despite what has occurred with the men, it is an indifferent nature to
which Lennie returns.  For, the rabbits and the heron are still in their places. 
Additionally, by repeating this scene at the end of his narrative, Steinbeck connotes
the cyclical nature of the lives of George and Lennie, a desperate cycle of alienation
in the desperate time of the Great
Depression.

The
bunkhouse

The setting of the bunkhouse is
one in which the men are in conflict as well as one in which George and Lennie must be
on guard as the alienated men are mistrustful of one another. In addition, Steinbeck
uses this setting to portray the social inequities of society with Crooks segregated
from the others, Candy threatened by his old age and disability, and Curley irrationally
defensive of his position as the son of the boss, itching for a fight constantly because
of his alienation from the other men.

The
stable buck's room

Where Crooks, the black
stable buck, stays in the barn is a completely isolated area.  There Lennie, who
represents the yearnings of all the dispossessed, enters and talks with Crooks who
finally opens up his heart to the simple man.  Crooks expresses the terrible isolation
of men who have no one by whom to "measure" themselves.  In this setting especially,
Steinbeck expresses his motif of the importance of the fraternity of
men.

The
barn

As a shelter for animals, Steinbeck
returns here to his Naturalistic motif as Lennie's animalistic characteristics lead to
his unintentional act of murder as he strokes Curley's wife's hair too hard just as he
stroked the newborn puppy too hard.  This hollow location symbolizes the death of all
the dreams of Lennie and George.

The shelter for animals is
an appropriate setting for the climax and death of the dream as it has been animals such
as the dead mouse, the dead dog of Candy and the dead puppy that have foreshadowed
Lennie's, who is describes in zoomorphic terms--his
paws--death.