Figure 1. Map showing the St. Clair River, which flows from Lake Huron to Lake St. Clair between Michigan and Ontario, Canada. The primary study area is the northernmost part of the river. Two site-specific survey areas—Marysville, MI, and Port Lambton, Ontario—also are shown. The Fort Gratiot CORS (Continually Operated Reference Station) was used to post process navigation to RTK positions (National Geodetic Survey, 2009). Click on figure for larger image.