What were people called who arrived early to claim land during the Oklahoma Land Rush in 1889?

People who arrived early to claim land slightly before the Oklahoma Land Rush in 1889 were called Sooners. The name came from a section of Proclamation 288 in which it stated whoever came early and took the land were not able to keep their land, therefore they had to wait the same time as everyone else (until it was legal to take land).

They were called Sooners. Because of how soon they came to the area.