The ancestral Puebloan flute (at one time called Anasazi) is one of the oldest instruments in North America.  In 1931, Earl Halstead Morris (1889–1956),  lead an expedition to the Prayer Rock district of North Eastern Arizona. His team unearthed thousands of artifacts. Six flutes were found in the “broken flute cave” in north-eastern Arizona not far from the Canyon de Chelly. Since this was the period of the basket maker culture. These are often called Basketmaker flutes.  The six flutes that were found there were made from box-elder, a variety of maple.  They are some of the oldest wooden flutes of North America. 

The flute that I use as a prototype is a six-hole flute, and is the only one that was played.  This flute is in the key of B-flat, and plays a major pentatonic scale.  A wealth of information on the history of flutes is available at Clint Goss'  flutopedia site.