The John Day Lock and Dam, 24 miles upriver from The Dalles [1] and six miles east of Stonehenge, gave birth to Lake Umatilla and produces enough electricity for two cities the size of Seattle [2].
Here you’ll find one of the largest single-lift locks in the world, hefting vessels 113 feet. At the dam on Oregon’s I-84, enjoy the fish-viewing room, visitors’ gallery, and Giles French Park, which has a boat launch, a picnic area, and fishing.
A good portion of the power generated is used in the enormous Columbia Aluminum Corporation plant that stretches for two-thirds of a mile next to the dam.
Camp for free at undeveloped Cliffs Park, approximately three miles off the highway on John Day Road.
Links:
[1] http://www.moon.com/destinations/washington/columbia-gorge-and-wine-country/the-columbia-gorge/the-dalles
[2] http://www.moon.com/destinations/washington/seattle