Port Huron sits where Lake Huron becomes the St. Clair River, and where the Blue Water Bridge connects Michigan to Ontario. In the old world, it was a border crossing. In the GLMZ, it is the border crossing — the primary point of jurisdictional transfer between American corporate territory and Canadian sovereign space on the Lake Huron corridor. Every person, cargo container, and data packet crossing between the Blackpipe Corridor on the Canadian side and the Michigan interior passes through Bluewater Checkpoint, and the infrastructure required to process that traffic has consumed the city.

The bridge itself has been widened, reinforced, and augmented with a scanning array so dense that crossing it takes a minimum of 45 minutes even with clean documentation. The scanning isn't just customs — it's jurisdictional assessment. Your legal status, your augmentation registry, your corporate affiliations, your tier rating — all of it is evaluated in real-time as you cross, and your rights on the other side are calculated accordingly. The process is automated, which means it is fast, impersonal, and essentially impossible to appeal. The checkpoint authority — a joint operation between Tessera Corponation (American side) and the Canadian Border Authority — has more practical power over individual lives than any court in the region.

The city behind the checkpoint is a border economy amplified to industrial scale. Legal services, document preparation, identity verification, augmentation compliance adjustment — an entire industry built around helping people survive the crossing. The south side of town, away from the bridge, retains some of the old Port Huron character — lakefront parks, residential neighborhoods, the remnants of a beach town that existed before the border became an industry. These neighborhoods are where the checkpoint workers live, and they carry the particular weariness of people whose daily work involves watching a machine decide other people's futures.