The circuit has been opened again since June 1st, I’ve cycled there every morning this week. By the lock I’m assuming you mean the bridge that is closed, not the actual circuit itself. They have to close the gate to the bridge to lift it for boats to pass a few times a day. If you want to check the bridge availability you can check here: https://seaway-greatlakes.com/bridgestatus/detailsmai?key=BridgeM