Simplify the following text for a Grade 4 native English-speaking person.
Original: Its original name was Beaver City , and was planned to be the capital of the short-lived Cimarron Territory . In 1890 , the territory was assigned to Oklahoma Territory , and Beaver City became the seat for the entire Oklahoma Panhandle , then known as Seventh County .
Simplified: Beaver is a city of Oklahoma in the United States .