Bonneville Lock & Dam

The Bonneville Lock & Dam spans across the Columbia River, joining the states of Oregon & Washington. It is located in the Columbia River Gorge National Scenic Area about 40 miles east of Portland & Vancouver. The U.S. Army Corps of Engineers operates & maintains both the lock & dam, the latter which has been used for hydroelectric power production since 1938. It is free to visit both the dam & lock & there are regular guided tours of various parts of the site.

The dam, a lock & the original powerhouse were constructed by the Corps of Engineers on the south (Oregon) side of Bradford Island, & the built the spillway on the north (Washington) side. Construction started in 1933 and was completed in 1937. Before the river was dammed at this location, a set of locks (that were opened in 1896) moved ships around Cascades Rapids, which is several miles upstream of Bonneville. When the dam was complete & the river allowed to flood to create the reservoir, both the cascades & the old lock structure were submerged. When the original navigation lock at Bonneville was opened in 1938 it was the largest single-lift lock in the world. As the dam is in constant use, you aren't able to visit the spillway, but there was a good vantage point just outside the visitors centre that gave a great view of the turbulent water as it passed under the open spillway gates.

To cope with added power demands, a second powerhouse & dam structure was commisioned. Construction commenced in 1974 & was completed in 1981. The second powerhouse was built by widening the river channel on the Washington side & provided a combined electrical output of more than 1 million kilowatts. The 'new' powerhouse isn't part of the tour but we were able to go inside the original powerhouse to view the turbines. The Corps of Engineers are currently renovating & upgrading the turbines which meant that you were able to see what the turbines looked like when dismantled - cool!

Despite the world record size when constructed, the original Bonneville Lock soon became the smallest of seven locks subsequently constructed at different locations upstream on both the Columbia & Snake
Rivers. A new, larger lock was constructed on the Oregon side of the river which opened in 1993. The old lock is still present but is no longer used for river traffic. I watched a boat use the lock, but I didn't look around the visitors centre as it was getting late & I wanted to find the hotel & check in before I had to return the car.