Three Mile Falls Dam is located at river mile three on the Umatilla River. The dam was constructed in the early 1900s and serves as an irrigation dam that is a complete barrier to fish migrating upstream. In order to successfully migrate past the dam, all adult salmon and steelhead must use the fish passage facility located on the east side of the dam. The fish facility consists of a fish ladder, viewing window, fish trap and holding pond. Every adult salmon and steelhead heading upstream is counted at this facility using a combination of trapping and video tape enumeration. When the facility is in trapping mode, fish are sampled for biological data, collected for hatchery broodstock, or hauled and released upriver during times of inadequate passage in the lower river. The facility is run through a cooperative project by The Confederated Tribes of the Umatilla Indian Reservation and by the Oregon Department of Fish and Wildlife.

The facility counts summer steelhead from September through May, spring chinook from April through July, fall chinook from August through December, and coho from September through December.

For any additional questions please contact Wes Stonecypher, fish passage biologist with the Oregon Department of Fish and Wildlife, at 541-276-2344.