Steinbeck's novel is, in some ways, a tale of two cities: Weed and Soledad. What happens to Lennie and George in Weed anticipates what happens to them in Soledad. Lennie's alleged sexual assault of the woman in Weed foreshadows the encounter with Curley's wife in Soledad.
The mere names of these two towns also hint at the hardship that Lennie and George face. The name Weed implies an unpleasant growth that might spoil an otherwise pleasant landscape. Even more striking is Soledad, a Spanish word that can mean "solitude," "isolation," and even "grief."
On the barley farm near the town of Isolation, we find many characters who are alone. Curley has a wife who has an eye for other men. Candy has an old dog, but this dog is "put out of his misery", which leaves the old swamper even more lonely. If the farm workers want female companionship, they have to go into town to a house of prostitution. The African-American character, Crooks, is isolated from the other men because of the color of his skin.
Ultimately, the most prominent characters in the story all long to be in some sort of setting where they won't feel so alone and where they will feel needed. Such a dream draws Candy into wanting to go in with George and Lennie in buying their "dream" house. Eventually, the greatest joy in life is having someone with whom to share it. As Lennie cries out,
"We got each other, that’s what, that gives a hoot in hell about us...”
Thus, a novel set near the town of Soledad has much to say about solitude and lonliness.