2019 Soo Locks Engineers Day, June 28; Soo Locks Park in Sault Ste. Marie. John Gonzalez of MLive talks to Linda Hoath of the Sault Ste. Marie CVB. Once again the Soo Locks will open its doors to the public for its annual open house -- Soo Locks Engineers Day (Friday, June 28). The U.S. Army Corps of Engineers invite you to explore the Soo Locks and get a rare opportunity to walk across the Lock walls. These walls make it possible for freighters to traverse the 21-foot drop between Lake Superior and the lower Great Lakes. Hours are 9 a.m.- 4 p.m. The park and all facilities are open free to the public and parking is located on Portage Avenue.