YANKTON, S.D.(WNAX)- The history of the Pick-Sloan Plan that led to construction of the six main stem dams on the Missouri River was highlighted at the annual meeting of the Missouri Sedimentation Action Coalition.

The meeting, held virtually, featured historian Michael Lawson who said much was lost in building those dams.

Lawson had a list of benefits other states got from the project.

Lawson says another major promise of the project was totally lost.

The coalition was formed to find solutions to the increasing siltation of Lewis & Clark Lake. It’s estimated that about thirty percent of the capacity of the lake has been filled in since Gavins Point Dam was built in the late 1950s.