| Rock Island to Silver Firs (Washington) | 1,600.36 mi (2,575.53 km) |
| Rock Island to Silver Spring (Maryland) | 734.51 mi (1,182.07 km) |
| Rock Island to Silver Springs Shores (Florida) | 979.82 mi (1,576.86 km) |
| Rock Island to Silverdale (Washington) | 1,624.17 mi (2,613.84 km) |
| Rock Island to Silverton (Oregon) | 1,628.05 mi (2,620.10 km) |
| Rock Island to Simi Valley (California) | 1,606.57 mi (2,585.52 km) |
| Rock Island to Simpsonville (South Carolina) | 648.90 mi (1,044.30 km) |
| Rock Island to Sioux City (Iowa) | 306.51 mi (493.28 km) |
| Rock Island to Sioux Falls (South Dakota) | 344.17 mi (553.89 km) |
| Rock Island to Skokie (Illinois) | 151.65 mi (244.06 km) |
| Rock Island to Sleepy Hollow (New York) | 866.68 mi (1,394.79 km) |
| Rock Island to Slidell (Louisiana) | 773.83 mi (1,245.36 km) |
| Rock Island to Smithfield (North Carolina) | 777.98 mi (1,252.04 km) |
| Rock Island to Smithfield (Utah) | 1,094.22 mi (1,760.98 km) |
| Rock Island to Smithville (Missouri) | 254.30 mi (409.26 km) |
