This volume of the Collections of the Minnesota Historical Society is devoted to a historical discussion by Jacob Vredenberg Brower (1844-1905) about the source and headwaters of the Mississippi River, combined with his extensive hydrographic and topographic surveys. Brower summarizes the major European and white American exploratory trips to the area. Based on a scientific survey of the Itasca Basin that he made under the authority of the Minnesota Historical Society, Brower concludes that the true source of the Mississippi is neither Itasca Lake nor Elk Lake, nor even the stream discovered by Jean N. Nicolet (1836) called "Nicolet's Infant Mississippi River," but the "Greater Ultimate Reservoir" which receives its water supply from aerial precipitation and stores it in various component lakes and springs. Some of these lakes include Hernando de Soto, the Triplets, Whipple, Morrison, and Floating Moss; the streams that proceed from them include the beginnings of the Nicolet as well as the Mississippi. From Nicolet's middle lake the main river proceeds "in an unbroken channel" to the Gulf. After lobbying successfully to have this headwater region preserved as Itasca State Park (1891), Brower served as its first commissioner. The appendix includes an historical account of how the Mississippi and the Lake of the Woods came to form part of the northwestern boundary of the United States. Its author was Albert James Hill (1823-1895), who was also instrumental in the creation of Brower's report.