 Several efforts were made to determine the source of the Mississippi River . In 1823 Italian explorer Giacomo <unk> <unk> who had split from the Long expedition in Pembina , found Lake Julia which he believed was the source of the Mississippi River . The actual source was found in 1832 , when Henry Schoolcraft was guided by a group of Ojibwe headed by <unk> ( " Yellow Head " ) to a lake in northern Minnesota . Schoolcraft named it Lake <unk> , combining the Latin words <unk> ( " truth " ) and <unk> ( " head " ) . 
