MISSOULA - A $6.5 million project is under way to help fish navigate over the Thompson Falls Dam on the Clark Fork River in northwest Montana.

PPL Montana owns the dam, which is located northwest of Missoula.

PPL Montana spokesman David Hoffman says the fish ladder has been designed to help bull trout and other species get over the dam to access hundreds of miles of rivers upstream.

The project features a series of steps for the fish. At the bottom of the ladder there will be some turbulence to imitate natural falls which attract the fish. The fish will then go up the man-made steps that simulate steps in the rock in the original falls. They'll be able to swim up 50 steps and get into the river through a 40-inch tube.

The fish ladder is expected to be complete by December 2010.