MN DNR adds about 1,250 clams to three Mower sites in Sept. — Austin, Minn. — Sept. 23, 2022 — Standing in the Cedar River, Madeline Pletta was about to start walking upstream to drop native clams in the water when she spotted an old friend. Pletta, a state mussels propagation biologist, spotted a black sandshell mussel on the bed of the Cedar…