Discovering the Mississippi River
As expeditions led by Lt. Zebulon Pike and 1805, and General Lewis Cass in 1820, had arrived in Minnesota as far north too late in the season to reach the Mississippi River headwaters, Henry Rowe Schoolcraft was commissioned by the American Government to treaty with natives in the area and to determine the true source of the Mississippi River. Guided by the Chippewa natives, he was the first person of European descent to see the lake he would name Itasca in
mid July of 1832.

Naming the Mississippi River
Schoolcraft came up with the name Itasca by linking together the last four letters of the Latin word veritas and the first two letters of the Latin word caput.
Veritas is truth; caput is head. Therefore, Itasca stands for the true head (waters) for the Mississippi River. In 1836, yet another explorer was sent to confirm Schoolcraft's conclusion. Jean Nicolas Nicollet declared in his journal that the longest of the streams that feeds Itasca, now known as Nicollet Creek, was truly the infant Mississippi according to geographic rule. Schoolcraft's Lake Itasca remained uncontested, however, as the official source of the Mississippi River.

The origin of Capt. Willard Glazier's Source of the Mississippi Headwaters Map, 1887
It was not until 1881, 45 years after Nicollet's expedition that Glazier began exploring the lakes and streams that comprise the headwaters of the Mississippi.
This is the map Glazier laid down to illustrate his journey of exploration by canoe which began July 12,1881 from Brainerd, Minnesota. According to Glazier's journal (which some have dismissed as largely fabricated) Lake Itasca is fed by Lake Glazier which in turn is fed by three creeds, one of which is fed by tiny Lake Alice.

All sizes are approximate.