They worked south of Soledad, in the Salinas Valley, Caifornia and were running away from the town of Weed, due to Lennie's troubles when they worked there.
Lennie died in the ranch in Soledad.
Lennie died next to the little pool of water by the river. By the description of this location in the beginning, it's just a little ways off the main road through a path. A serene location, many a campfire might have taken place in this hide-a-way spot. In the first chapter, George tries to make sure Lennie knows this location well just in case there is any trouble. In the end of the book, George tries to put Lennie's mind in the fictional farm they have been talking about throughout the book to the point at which Lennie can almost see it in the distance.
The place they came from was called Weed. The town the ranch they work for the majority of the book is close to Soledad.
In the book “Of Mice and Men” by John Steinbeck, Lenny and George travel to a rural area in California. They come upon a riverbed of the Salinas river, a short distance off of the highway. It is a beautiful place that is at the base of the “golden foothill slopes.” The riverbed with its beauty will become the place where George has to shoot Lenny in the head. It is where Lenny dies in the end.
The story takes place on a barley ranch in Salinas, California. Steinbeck was from the area and this is one of his novels in which he takes his characters to the area where he grew-up. The scene is in the 1930's during the depression.