The St. Louis River, the largest U.S. tributary to Lake Superior, drains 3,634 square miles, entering the southwestern corner of the lake between Duluth, MN and Superior, WI. The river flows 179 miles through three distinct areas; coarse soils, glacial till and outwash deposits at its headwaters; a deep narrow gorge at Jay Cooke State Park; and red clay deposits at its lower reaches.

As the river approaches Duluth and Superior it takes on the characteristics of a 12,000 acre (4856 hectare) freshwater estuary. While the upper part of the estuary has some wilderness-like qualities, the lower portion is decidedly urban. The RUSS will be located in this lower urban portion.

The WOW sampling equipment is located on the wall of the Duluth Ship Canal. Data collected includes temperature, conductivity, and turbidity. Thanks to the USGS, we are also able to get real-time discharge data.