The correct answer to this open question is the following.
Although you forgot to include the options for the question we can say the following.
In the mid-1800s, pioneers who traveled through the Great Plains to the West faced steep passes and difficult terrain.
Let's remember that in those years, the Great Plains was a difficult place to cross or settle because of the conditions of the land and the weather.
The Plains was the site of the Dust Bowl during the 1930s
In that time, a severe drought followed the removal of native grasses and strong winds blew away topsoil and created a Dust Bowl.
In the 1930s, the Great Plains lived difficult moments when severe dust storms hit this region of the United States. The dryness due to lack of water, the removal of native grasses, combined with climate conditions, produced these dust storms that killed animals and ruined the crops. There was no way to keep on farming the land and people had to move to the Pacific West, to California, where they had to start a new life.
