The River

Chesapeake by James A. Michener:

"The Susquehannocks...felt intuitively that they should be on the warpath, proving their manhood."  "...an old warrior predicted...when the day comes that we are afraid to fight, we lose the river."

Pentaquad, the first main character encountered, was an outcast of the Susquehannocks.  He paddled down the river towards the legendary Chesapeake Bay, where he found wading birds and plentiful flora and fauna.