The Minnesota River near Shakopee is the stretch of the river upstream of the Blue Lake Wastewater Treatment Facility. Many areas next to this stretch of the river are part of the Minnesota Valley National Wildlife Refuge. Riley and Bluff Creeks flow into this section of the Minnesota River just downstream from downtown Shakopee. The Minnesota River at Shakopee, River Mile 25.1 has been used as a backup sampling site when the site at Jordan (River Mile 39.4) was inaccessible.The Minnesota River is a 332 mile long tributary of the Mississippi River which originates from Big Stone Lake near the border of South Dakota and Minnesota. It flows into the Mississippi River near Ft. Snelling in St. Paul. The watershed of the river covers roughly 17,000 square miles. The geology of the watershed is relatively young compared to other areas of Minnesota, and as a result there is a lot of erosion activity in the Minnesota River and its tributaries. Much of the watershed has been converted into cropland to take advantage of the nutrient rich soil in the region.