Simplify the following text for a Grade 9 native English-speaking person.
Original: The Niagara Falls are voluminous waterfalls on the Niagara River , straddling the international border between the Canadian province of Ontario and the U.S. state of New York .
Simplified: Niagara Falls is the group name of three big waterfalls on the Niagara River in eastern North America , on the border between the United States and Canada .