| 100% | RIO | 3 | ___ Grande (river that borders El Paso) |
| 59% | RIO | 3 | ___ Grande (river that borders Brownsville, Texas) |
| 56% | POTOMAC | 7 | River that borders Washington, DC |
| 55% | RIO | 3 | ___ Grande (El Paso/Juárez river) |
| 53% | RIO | 3 | ___ Grande (river that serves as a natural border) |
| 50% | PECOS | 5 | River that empties into the Rio Grande |
| 50% | OHIO | 4 | River that forms Kentucky’s northern border |
| 50% | STMARYS | 7 | River that forms the Michigan-Ontario border |
| 50% | OHIO | 4 | River that forms Kentucky's northern border |
| 50% | RIO | 3 | ___ Grande (river between El Paso and Ciudad Juárez) |
| 49% | OHIO | 4 | River that forms much of Kentucky's border |
| 49% | ZAMBEZI | 7 | River that is bordered by Zambia and Zimbabwe |
| 48% | MORAVA | 6 | River that forms the border between Slovakia and Austria |
| 48% | GUADIANA | 8 | River that forms part of the Spain-Portugal border |
| 48% | RHINE | 5 | River that forms part of the France/Germany border |
| 48% | MEKONG | 6 | River that forms the border between Laos and Myanmar |
| 48% | WABASH | 6 | River that forms part of the Illinois-Indiana border |
| 48% | MEKONG | 6 | River that forms much of the Laos/Thailand border |
| 48% | RIO | 3 | ___ Grande (Texas border river) |
| 48% | RIO | 3 | ___ Grande (southwestern border river) |
| 47% | NIAGARA | 7 | River that forms part of the U.S.-Canada border |
| 47% | ODER | 4 | River that forms part of the border between Germany and Poland |
| 47% | TAMAR | 5 | River that forms most of the border between Cornwall and Devon |
| 47% | ORINOCO | 7 | River that forms part of the border between Colombia and Venezuela |
| 47% | MOSELLE | 7 | River that forms part of the border between Germany and Luxembourg |
| 47% | DOURO | 5 | River that forms part of the border between Spain and Portugal |
| 47% | LIMPOPO | 7 | River that serves as the border between Zimbabwe and South Africa |
| 47% | RIONEGRO | 8 | River that forms part of the border between Colombia and Venezuela |
| 46% | RIO | 3 | ___ Grande (U.S./Mexico border river) |
| 46% | PECOS | 5 | River that flows from New Mexico through Texas to the Rio Grande |