| distance | reference number | name | latitude | longitude |
| 509.8 | 503 | Chain Bridge, Washington, D.C. | 38.9333 | -77.1167 |
| 511.2 | 502 | Chain Bridge, one mile below, Washington, D.C. | 38.9167 | -77.1 |
| 513.4 | 1495 | Key Bridge, Washington, D.C. | 38.9 | -77.0667 |
| 515.9 | 1051 | Fredericksburg, Rappahannock River, Virginia | 38.3 | -77.45 |
| 516.0 | 2475 | Quantico Creek, Virginia | 38.5167 | -77.2833 |
| 516.4 | 88 | Aquia Creek, Virginia | 38.4167 | -77.35 |
| 516.5 | 1266 | High Point, Occoquan Bay, Virginia | 38.6167 | -77.2 |
| 516.5 | 3268 | Washington, Potomac River, D.C. | 38.8733 | -77.0217 |
| 516.7 | 2509 | Reagan National Airport, Washington, D.C. | 38.85 | -77.0333 |
| 517.3 | 222 | Bellevue, Washington, D.C. | 38.8333 | -77.0333 |
| 517.4 | 750 | Deep Point, Mattawoman Creek, Maryland | 38.5667 | -77.2167 |
| 517.8 | 59 | Anacostia Bridge, Anacostia River, Washington, D.C. | 38.8667 | -77 |
| 517.9 | 1377 | Indian Head, Maryland | 38.6 | -77.1833 |
| 518.0 | 1183 | Gunston Cove, Virginia | 38.6667 | -77.1333 |
| 518.4 | 35 | Alexandria, Virginia | 38.8 | -77.0333 |
| 518.4 | 233 | Benning Bridge, Anacostia River, Washington, D.C. | 38.9 | -76.9667 |
| 518.6 | 1660 | Liverpool Point, Maryland | 38.4667 | -77.2667 |
| 518.7 | 273 | Bladensburg, Anacostia River, Maryland | 38.9333 | -76.9383 |
| 519.1 | 1767 | Marshall Hall, Maryland | 38.6833 | -77.1 |
| 519.3 | 1903 | Mount Vernon, Virginia | 38.7 | -77.0833 |
| 519.4 | 1776 | Massaponax, Rappahannock River, Virginia | 38.25 | -77.4167 |
| 519.7 | 1114 | Glymont, Maryland | 38.6167 | -77.1333 |
| 520.4 | 591 | Clifton Beach, Maryland | 38.4167 | -77.2667 |
| 521.2 | 1041 | Fort Washington, Maryland | 38.7167 | -77.0333 |
| 521.2 | 2553 | Riverview, Maryland | 38.7167 | -77.0333 |