| Answer | Crossword Clue |
|---|---|
| ERIE | Part of U. S.-Canadian boundary. |
| ERIE | Lake on the U.S.-Canadian boundary |
| BALTIC | A boundary of U.S.S.R. |
| RIOGRANDE | U. S. boundary river. |
| RIOGRANDE | U.S.-Mexican boundary |
| ARAS | Iran-U.S.S.R. river boundary |
| AMUR | U.S.S.R.-China river boundary |
