| Border | River | % Correct |
|---|---|---|
| Missouri and Illinois | Mississippi | 91%
|
| Mexico and Texas | Rio Grande | 91%
|
| Germany and France | Rhine | 87%
|
| Bulgaria and Romania | Danube | 84%
|
| Iowa and Nebraska | Missouri | 75%
|
| Arizona and California | Colorado | 74%
|
| Jordan and Israel | Jordan | 67%
|
| Myanmar and Laos | Mekong | 66%
|
| Indiana and Kentucky | Ohio | 61%
|
| New York and Ontario | St. Lawrence | 60%
|
| Virginia and Maryland | Potomac | 56%
|
| Zimbabwe and Zambia | Zambezi | 56%
|
| Washington and Oregon | Columbia | 42%
|
| Texas and Oklahoma | Red | 40%
|
| New Jersey and Pennsylvania | Delaware | 34%
|
| Germany and Poland | Oder | 32%
|
| Namibia and South Africa | Orange | 32%
|
| Russia and China | Amur | 30%
|