Simplify the following text for a Grade 7 native English-speaking person.
Original: A group of these Native Americans were , in deeds and correspondence , known as the Sepasco Indians , a name specific to Native Americans in the Sepasco area ( modern-day Rhinebeck ) .
Simplified: A smaller group of these Native Americans were known as the Sepasco Indians . This name was used for Native Americans in the Sepasco area , which is now known as Rhinebeck .