15 Things You May Not Know About Rock Island Dam

1. Rock Island Dam was the first dam to span the Columbia River.

2. Traveling by river you would have to go 235 miles upriver to reach the Canadian border and 453 miles downriver to reach the Pacific Ocean.

3. Rock Island Dam was expanded during the years 1951-53 primarily to accommodate the power needs of the Alcoa plant built south of Malaga, WA.

4. Rock Island Dam contains 19 generators (11 in the first powerhouse and 8 in the second).

5. Across the front of Rock Island Dam are 31 spillway gates.

6. The Rock Island Dam site was found by engineers working for a Boston company that managed Seattle based Puget Sound Power & Light in 1927.

7. The turbines installed in the second powerhouse at Rock Island Dam between 1974 and 1979 were the largest in the world at the time of installation.

8. At peak generating capacity, Rock Island Dam generates 693,000 kilowatts.

9. The second powerhouse was built in 1979.

10. The rock that Rock Island Dam is anchored to is basalt.

11. The total length of the spillway is 1,424 feet.

12. The spillway is semi-unique in that it is divided in the center by a fishway. There are 14 spillway gates on the east side of the dam and 17 gates on the west side.

13. The original generators were rated at 15,000 kilowatts, after being upgraded three of the four are now rated at 20,700 kilowatts.

14. The total output of Rock Island Dam can power a city the size of Vancouver, WA.

15. Construction of the first powerhouse was completed in 1933.