The Joad and Wilson families made their way slowly through New Mexico and into Arizona. There they were stopped by the border patrol to make sure they are not bringing any agricultural materials, such as plants, into the state. They are also required to state how long they are going to stay and why they are in Arizona. From there they pass through the mountains and into California.

Pa is excited to finally be in California, but Tom realizes this was just the beginning of the most dangerous part of their journey, because they have to travel across the desert next. After the desert is their final destination, the part of California with the vineyards and orchards, these are the places which hold the hope of employment and a better life.

They decide to stop near a river where eleven tents are already erected. The woman they speak to tells them they can stay, but to be aware the cops will come and check them out. They decide to stay because of the water, and the fact they were all tired and in need to rest. Granma is not doing well at all, she keeps on calling out for Grampa, and she does not know where she is or who is with her.

The men decide to bathe in the waters of the river. There they meet a man and his son, who are traveling back east because they cannot find decent work in California. The father tells Tom, Pa, Alan and Casy his story of how he was treated in California. He acquaints them with the term, Okie. This is slang for a person who comes from Oklahoma, but in California it is slung at the migrant workers as slur. He tells Tom and the rest about the hatred the Californians have for the people from Oklahoma. He explains they are scared the Okies are going to take their jobs and food. He also tells them it is almost impossible to buy land in California, because it is mostly owned by big land owners. The Joad men tell him they have to keep on going and hope it will not be as bad as what the man is telling them.

Noah, Tom's older brother, has decided he will not go the rest of the way into California. He wants to live by the river and eat the fish he catches. He tells Tom to tell his mother about his decision. Tom tries to talk him out of it, but he is steadfast in his decision. Ma is sad that he is not coming with the rest of the family, but she copes because she is at the end of her rope and cannot take in any more bad news.

The police visit the tent Ma, Granma and Rosasharn are in. Ma and the policeman have words about how he is treating them in an unkind manner. He does not care and tells her if the family is still there in the morning, he will arrest them. This combined with a woman from the Jehovites telling her Granma is going to die soon, has Ma gathering the family together so they can leave quickly. The Wilsons decide not to make the journey though the desert with the Joads, because Sairy is too ill to travel. She knows she is dying, but does not want her husband to know.

The Joads make the slow long journey through the desert and arrive to see the green of the fertile valley. The family is excited by the view of the trees and grass, but are saddened to hear from Ma that Granma has died on the trip through the desert. They also realize their last forty dollars might have to be spent paying for Granma's funeral.

The fertile farms of California were once the property of the people of Mexico. Then the Americans came and took whatever land they wanted through force and determination. They used the land and decided it was theirs, because they were the people who tilled the soil. Now the grandchildren of these squatters own the land their forefathers stole. They are afraid the new people coming into California, the people from Oklahoma, Kansas and other states, will do to them what their ancestors did to the Mexicans. The people the landowners use to pick the crops are from China, Japan, Mexico, and the Philippines, these people are paid low wages and have poor housing conditions, which is how the landowners like it. The landowners feel these people do not know any better, so it is acceptable to take advantage of them. They are afraid of the farmers coming into the state, because they know how to farm and what it means to farm. They are not so far removed from the farm that it does not have meaning to them unlike the landowners.

The current workers fear the new people, because they are so hungry they will work for whatever they can get. Then the landowners will pay less to everyone and this will cause hardship for old and new workers. The shopkeepers and bankers do not like the new people, because they have no money to spend.

The police, who work for the landowners, are trying to get rid of the migrant workers by tearing down their Hooverville. These are the communities the migrants live in, which are made up of houses that are either tents or made of cardboard. The landowners know if these people unite they can over throw the landowners, just as their forefathers did to the Mexicans.

The Joads have unwittingly come into a situation in which there is a great deal of animosity between the migrants and the local people. They have to keep on going, but they know they will face prejudice and trouble. They are also suffering from the loss of Granma and Noah's decision to stay by the river.