Natural Features & Ecosystems

Discover the prairie and savanna ecosystems at Arcola Mills Day Use Area.

NPS/Daniel Peterson

Relatively free-flowing and unpolluted, the Namekagon and St. Croix Rivers flow through some of the most scenic and least developed country in the Upper Midwest. In 1968, Congress established the St. Croix National Scenic Riverway (Riverway), which includes the Namekagon, as one of the orginal eight rivers protected under the national Wild and Scenic Rivers Act. In 1972, the Lower St. Croix National Scenic Riverway was added to the system. Together they form the 230-mile-long park that offers scenic views and spectacular recreational opportunities.

The Riverway is diverse in character with sedate stretches flowing along marshes and scrub, and rocky stream segments. The Namekagon river is tinted dark brown from tannins, in contrast to the dark greens of the conifer trees. Wild rice in the lake-like Pacwawong flowage waves in the breeze. The Namekagon and Upper St. Croix River is dominated by northern forest types containing a mix of red, white and jack pine, aspen, birch, spruce and balsam fir.

As the Namekagon meets the confluence to the St. Croix River, the corridor widens. These soils support prairies, savanna, and oak and pine forests. Further downriver, deciduous trees begin to dominate, animals tend to be observed at a greater distance, the banks of the river are lower in places, and geologic features become more prominent after the hydroelectric dam in St. Croix Falls/Taylors Falls.

One mile below the St. Croix Falls hydroelectic dam, the river flows through the Dalles, a rocky gorge 70 to 100 feet deep in places. It is a place of dramatic scenery bordered by two states, one in Wisconsin and one in Minnesota. Downstream of the Dalles, the St. Croix River widens and shallows as it passes between high, wooded banks dominated by moist hardwood forests containing red oak, American elm, ash, maple and basswood.