Water resources of the Rum River Watershed, east-central Minnesota

The Rum River, a tributary of the Mississippi River, drains an elongate area of about 1,550 square miles. The source of the Rum River is Mille Lacs Lake. Much of the northern half of the watershed is forested, and there are large areas of swampland. Population is most concentrated in the southern half, where agriculture is the dominant economic activity.

Except for scattered Precambrian igneous rock outcrops in the central third of the watershed, bedrock is covered by glacial drift. In the southern third, the drift includes considerable amounts of outwash and is directly underlain by Cambrian and Precambrian sedimentary rocks.

Greatest topographic relief is in morainal areas around Mille Lacs Lake. The central third of the watershed slopes gradually southward, grading into the relatively flat area of surficial outwash.