Hi all, 

All of the birds in Belmont Bay are in Virginia.  Thompson Creek appears to enter Belmont Bay just north of the boundary of Mason Neck State Park.  The state boundary runs along the Potomac Shore of Mason Neck S. P., then angles out across the mouth of Occoquan Bay to the northeasternmost tip of Leesylvania S. P. to the southwest.  

Best, 

Rob Hilton
Silver Spring, MD