Opponents of breaching the four lower Snake River dams to recover threatened and endangered salmon and steelhead will hold an all-day symposium Thursday and make the case for keeping the structures blamed for driving the fish toward extinction.

The event hosted by the Citizens for the Preservation of Fish and Dams will be held at Walla Walla Community College in Clarkston and start at 8:30 a.m. Featured speakers include retired Army Corps of Engineers fisheries biologist John McKern, fishing outfitter Rusty Bentz and Jerry McGehee, a retired Idaho Fish and Game hatchery manager.