Potomac River

The Potomac River is a location that appears in Sonic X comic series published by Archie Comics. It is a river located in Washington, D.C..

Archie Comics
When Doctor Eggman found out about an alleged Chaos Emerald at Smithsonian Institute, he hid in the river with one of his robots, where he ordered the Rogue Rouge to head out and retrieve the emerald for him.