The sight of 1,500 rainbows dazzled visitors at Scharnberg Pond near Everly Saturday, but their gazes weren't fixed on the sky above.

Curious anglers and other onlookers crowded the pond's south shoreline to watch a mobile tank filled with rainbow trout get released into the frosty waters below. The fish, which were trucked in from a Decorah hatchery, needed no coaxing after they were released from the tank via pipeline into a large hole cut into the surface.

The stocking was organized by the Clay County Conservation Board and Iowa Department of Natural Resources (DNR) as part of a special...