Ft. Dalles has a lot more history that is missing that what can be seen by the casual tourist. It was the home to units of the 4th US Infantry Regiment when it was stationed on the west coast. From here troops moved into central Washington, in 1855, and these events started the Yakama War which lasted for nearly 3 years.
If you look towards the river you will see a school with a flag pole. The flag pole marks the approximate location of the flag pole when the fort was active.
If you are interested in the Indian wars of the Pacific Northwest then this is a must stop place. Otherwise, I might pass it up because there isn't much to see unless you're just happen to be in the area.