Lower Yellowstone Fish Bypass Channel

Fish Bypass Channel and Weir Replacement

A new 2.1-mile bypass channel on the lower Yellowstone River is helping to lure the endangered pallid sturgeon upstream to spawn.

Ames Construction built the channel and performed a weir replacement at the Intake Diversion Dam near Glendive, Montana. The dam diverts water into a canal for agricultural irrigation.

The bypass channel allows fish of all species to get around the new concrete weir after its height was raised two feet above the existing weir. But it was especially designed to assist the ray-finned sturgeon in travelling farther upriver to spawn their eggs. Built in 1905, the dam is believed to have contributed to a decline in the species’ population because fish were not able to pass over it. The project opens up 165 river miles of potential spawning and larval drift habitat for the fish, which can live up to a century and traces its ancestry to the Cretaceous period 70 million years ago.