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The south branch of the Forest River has cut through the beaches of glacial Lake Agassiz and carved a broad, densely wooded valley. The Forest River Biology Area consists of 160 acres of this broad river valley. Approximately 120 acres are gallery forest while the other 40 acres are prairie and old fields.

The river flows over an accumulation of rocks and gravel forming many small rapids and frequent sandbars within the area. Springfed creeks flow into the river, one of the biggest entering from the southwest. Beaver have dammed this creek and swamp formed. Numerous ravines from the prairie widen on terraces or bottomlands below. A difference in elevation of about 100 feet exists between the prairie and the river.

The north-facing slopes are characterized by a relatively narrow zone of bur oak skirting the prairie. Toward the river, oak is replaced by a mixture of paper birch, green ash, box elder, and basswood. Aspen forms an extensive stand overlooking the swamp on the southwest. Hop-hornbeam and American elm are confined almost entirely to the bottomlands and river banks.

Highbush cranberry, nannyberry, downy arrowwood, red osier, hazelnut and beaked hazel are the most abundant shrubs within the woodland. Chokecherry, Juneberry and hawthorn occur along the edges of the prairie tapering into the woodland. Among the interesting fortes present are bloodroot, false lily-of -the-valley, shinleaf, and trillium.

Ostrich ferns are abundant, while the rattlesnake fern and lady fern are rare. Liverworts and mosses occur along the creek banks. About 425 species of vascular plants have been recorded from the area.

Animals occurring in the area, at least seasonally, include beaver, badger, red fox, coyote, snowshoe hare, mink, red and gray squirrels, white-tailed deer, peregrine falcons, bald and golden eagles, wood ducks, and several warblers, three species of frogs, one species of toad, two species of turtles, one species of snake and 23 species of fish.

Forest River Biology Area has been designated an approved area in the National Register of Natural Areas by the Society of American Foresters.

Background Information: Site description and map available. It is used in biology field trips and research projects.

Facilities: None

DR. PAUL B. KANNOWSKI is chairman of the Biology Department at the University of North Dakota in Grand Forks, N.D. and editor of The Prairie Naturalist.