Of Mice and Men begins and ends in the same location—by the Salinas River. However, this is not the only example of how the author brings the reader back to the beginning of the story. For example, in the final chapter Lennie is at the edge of the water, drinking. However, he is not gulping water as he did in chapter 1. Herons and snakes are also present in both the beginning and ending scenes. Lennie also strikes the same pose both times. “He pushed himself back, drew up his knees, embraced them…” (6).
George and Lennie are originally in the brush on the riverbank because they have been run out of Weed. This is due to Lennie getting in trouble by grabbing a woman’s dress. The final chapter has Lennie in the same place—the brush—because he is in “trouble” for killing Curley’s wife. Although Lennie does not know it, there is a mob after him. This is similar to the way they left Weed.
Additionally, in both chapter 1 and chapter 6 Lennie is compared to a bear. In the opening scene Lennie is described in the following way: “… he walked heavily, dragging his feet a little, the way a bear drags his paws” (2). In the final chapter Lennie “came as silently as a creeping bear moves” (100). Lennie and George’s dream begins and ends in the same location.
It isn't specifically said in chapter one but in a conversation with Slim George revealed that the reason they had come to Soledad in the first place was because Lennie has been, let's just say more that enthusiastically 'petting' a girl dressed in red in the town Weed, which in turn caused them to be hunted by an angry town-mob, leaving them no choice but to flee. This is reflected/rounded in the ending of the novel when Lennie is again over-enthusiastically 'petting' Curly's wife (also a lover of the color red - mentioned when she is first introduced) ultimately killing her. George tells Lennie run and that he will come along too - only this time it's Lennie being hunted.
PS: I studied this a while ago so i'm a little foggy on the details, this was all I could remember off the hop of my head. Wish I could be of more hele, hope it answers your question.