| Name | What | Region | Country | Lat | Long | Elev Ft. | Pop Est |
|---|
| Illahee | city | Washington | United States | 47.61306 | -122.59556 | 0 | 59510 |
| Illia | city | Washington | United States | 46.67611 | -117.50333 | 997 | 81 |
| Ilwaco | city | Washington | United States | 46.30917 | -124.04194 | 0 | 2762 |
| Image | city | Washington | United States | 45.60917 | -122.58083 | 200 | 102450 |
| Impach | city | Washington | United States | 48.28833 | -118.23556 | 1797 | 64 |
| Inchelium | city | Washington | United States | 48.29694 | -118.19556 | 1466 | 100 |
| Independence | city | Washington | United States | 46.79917 | -123.15389 | 200 | 2639 |
| Index | city | Washington | United States | 47.82083 | -121.55389 | 1315 | 813 |
| Indian Beach | city | Washington | United States | 48.16333 | -122.52 | 213 | 3212 |
| Indian Village | city | Washington | United States | 48.57306 | -122.64944 | 111 | 4247 |
| Indianola | city | Washington | United States | 47.74722 | -122.52444 | 0 | 9410 |
| Inglesea | city | Washington | United States | 47.48583 | -122.35528 | 357 | 103998 |
| Inglewood | city | Washington | United States | 47.73111 | -122.22917 | 400 | 114313 |
| Inglewood | city | Washington | United States | 47.6225 | -122.06694 | 347 | 50804 |
| Interbay | city | Washington | United States | 47.64139 | -122.39472 | 157 | 128803 |
| Intercity | city | Washington | United States | 47.915 | -122.23389 | 505 | 106605 |
| Interlaken | city | Washington | United States | 47.15583 | -122.54056 | 285 | 82745 |
| Ione | city | Washington | United States | 48.74111 | -117.41611 | 1998 | 126 |
| Irby | city | Washington | United States | 47.35944 | -118.85 | 1450 | 126 |
| Ireland | city | Washington | United States | 45.65944 | -122.37111 | 662 | 8722 |
| Iron Springs | city | Washington | United States | 47.15972 | -124.18722 | 98 | 731 |
| Irondale | city | Washington | United States | 48.04222 | -122.77139 | 154 | 6924 |
| Irwin | city | Washington | United States | 47.69278 | -117.24361 | 2040 | 50967 |
| Island View | city | Washington | United States | 46.23944 | -119.22222 | 357 | 31171 |
| Islandale | city | Washington | United States | 48.44639 | -122.85639 | 19 | 748 |
| Issaquah | city | Washington | United States | 47.53028 | -122.03139 | 200 | 21006 |
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