Before Europeans arrived, the land that is now Fountainhead Regional Park was home to Native Americans. There is evidence of human habitation as many as 10,000 years ago. The area was likely occupied by Monacan and Algonquian tribes, since both settled along waterways such as Bull Run and the Occoquan River.

Piscataway Crossing Regional Park is named for a Native American tribe which once lived in the area and thrived from the abundance of the Potomac River.

The Piscataway were one of the tribes encountered by Captain John Smith during his early explorations of the Potomac River. At that time their capital town was in Maryland, across the Potomac River from where Mount Vernon would later be built, and next to Piscataway Creek.

Native Americans occupied the region as early as 10,000 years ago and archeological studies of Piscataway Crossing Regional Park have found evidence of human existence on the land there as early as 8,500 years ago. The land which is now Piscataway Regional Park was likely occupied by Monacan and Algonquian people at different times in history.