Lake Itasca (Wikipedia)Lake Itasca (/aɪˈtæskə/ eye-TASS-kə) is a small glacial lake, approximately 1.8 square miles (4.7 km2; 1,200 acres) in area. Located in southeastern Clearwater County, in the Headwaters area of north central Minnesota, it is notable for being the headwater of the Mississippi River. The lake is in Itasca State Park. It has an average depth of 20 to 35 feet (6.1 to 10.7 m) and is 1,475 feet (450 m) above sea level.
Ordovician (Wikipedia)The Ordovician (/ɔːrdəˈvɪʃi.ən, -doʊ-, -ˈvɪʃən/ or-də-VISH-ee-ən, -doh-, -VISH-ən) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period 485.4 million years ago (Mya) to the start of the Silurian Period 443.8 Mya.