Rainbow Dam

Rainbow Dam is a hydroelectric facility that stretches 322 meters across the Missouri River to harness water flow for power generation. The structure contains eight generating units that contribute to the region's electricity supply.

The facility was built in 1910 and began operating with eight generating units right away. Shortly after, in 1912, Montana Power Company took control of the installation.

The dam takes its name from a striking waterfall in the area that has long been part of local identity and landscape. From the surroundings, visitors can sense how the structure ties together human engineering and the river's natural power.

The site can be viewed from various spots near the river, giving good views of the structure and how water moves through the system. Best visibility comes from exploring different riverbank areas and outlooks along the surroundings.

Water flows through long pipes that extend over half a mile before returning to the river at another location downstream. This extended water route is an impressive technical detail that shows the system's complexity.

Location: Cascade County

Length: 322 m

GPS coordinates: 47.53440,-111.20500

Latest update: December 12, 2025 09:00