An obstructed pipe at the Clearwater Fish Hatchery located on the Lochsa River east of Lowell, Idaho has been blamed for the deaths of nearly 200,000 Chinook salmon smolts. The Idaho Department of Fish and Game says uncommon freezing temperatures and human error contributed to the losses. The smolts were awaiting release into the river when a water flow valve was obstructed by ice build up. Hatchery attendants, who are charged with clearing ice from the intake pipe routinely, failed to notice the plugged valve. Hatcheries in the Clearwater basin operate as part of a federal program aimed at replenishing fish losses from four lower Snake River dams.