INTERPRETATION OF TERRACES AND PROFILE OF THE SAUK RIVER, A TRIBUTARY OF THE MISSISSIPPI

The Sauk River is a tributary of the Mississippi River. I examined the Sauk River drainage basin in the vicinity of Rockville, Waite Park, and St. Cloud. The Sauk River has a total elevation change of eighty feet. There are two to three main terraces that follow along the Sauk River. The main terraces range from an elevation of about 1,030 feet to 1,120 feet. The drop in elevation on the Sauk River is very gradual near the Mississippi River inlet, but upstream the elevation rises fairly rapidly. The drainage pattern seems much more developed near the town of Rockville compared to the middle of the stream just before Waite Park. This is probably because of the higher elevation of the terraces near Rockville compared to the flat swampy area just before the Waite Park area. The Sauk River displays well-developed meanders near its confluence with the Mississippi. Five significant terraces have been identified on the topographic map. The elevations of the terraces from top to bottom are 1,100 feet, 1,070 feet, 1,060 feet, 1,050 feet and 1,030 feet. The bedrock geology in and around the Sauk River is mostly made up of St. Cloud and Rockville granite, and the depth to bedrock (Stearns County Geologic Atlas) ranges from 50 to 100 feet. The terraces record post-glacial modification of the landscape.