Did you ever wonder: why are there two different lengths recorded for the river? How did Lake Itasca get its name? Have those rocks always been there? Does the river ever freeze? Discover the answer to these mysteries about the Mississippi River and Lake Itasca an a walk to the headwaters from 2 p.m. to 2:30 p.m. Friday, September 22 starting under the porch at the Mary Gibbs Mississippi Headwaters Center.