TREMPEALEAU, Wis. – The Army Corps of Engineers is hosting an open house at its Mississippi River lock and dam at Trempealeau on Saturday. Time: 10 a.m. to 2 p.m. Free. Visitors can get a behind-the-scenes view of the 88-year-old structure and its Industrial Era mechanics. The occasion is part of Trempealeau’s annual Catfish Days celebration.