Originally built to divert irrigation water. Later a power plant was added to provide power for the construction of the Arrowrock Dam farther upstream. Arrowrock Dam was the largest in the world when built. Diversion Dam has a small parking lot across the highway which can be dangerous to cross. Parking lot is usually used by rock climbers on the local cliffs. The Boise River Greenbelt walking and biking path runs on the same side as the dam and is a better way to see the dam. There is a reader board that explains the history and use. Probably not a popular stop for people passing by on the highway.

It was a short scenic drive just outside the city. The dam is beautiful and plenty of parking across the street.

Sitting down and just watching the Boise Diversion Dam is beyond relaxing. In fact, it's downright mesmerizing. Whether you drive there, walk there, or ride your bike, you'll want to take a wide-brimmed hat and slather on the sunscreen—because you're going to stay awhile.

The Boise Diversion Dam built in 1909 is a historic structure in a scenic location on the Boise River along the Ponderosa Pine Scenic Byway (Idaho State Highway 21). There is a parking area and educational signage. The paved Boise River Greenbelt trail passes by, so this is a good location for a walk or bicycle ride.