They were sent to Camp Pendleton in California for basic Marine training and then brought together to undertake the specific task for which they had been recruited: developing the code.

The development of the code itself is a critical point that popular accounts often simplify.

The Navajo Code Talkers were not simply speaking Navajo over the radio.

Speaking an unbroken natural language, however obscure, would have provided some security — but a sophisticated intelligence service, given enough intercepted traffic, could potentially analyze the patterns of a natural language and begin building a vocabulary.

The code that the original twenty-nine men developed was something more sophisticated: a military communications system built on top of Diné Bizaad, using the language as its foundation while adding layers of specifically designed encoding.

How the Code Actually Worked