This activity is one of many great pre-planned lessons for you part of our free Keep’Em Flying Program at the National Museum of World War II Aviation. In this program, students take a learning styles questionnaire, and are placed in various “jobs” on a B-25 bomber based on what their individual learning style is. At the museum, students run a simulated mission – this job has students decoding a message telling them information that is vital to them and their classmates.

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In wartime, secure communications are crucial, but for the U.S. armed forces during WWII, securing messages became a bewildering problem. Japanese cryptographers, many of them educated in the United States and fluent in standard and colloquial English, were amazingly adept at breaking codes. Enemy forces often knew about American battle plans, and no defense against Japanese code breaking had materialized, try as we might. “Military communications were made available to the enemy like sand sifting through a sieve,” an analyst said. An unlikely answer came from an unlikely source.

The Navajo Code Talkers were a group of American Indians who joined the US Armed Forces and created a series of secret codes used for military communication.
The Navajos were assigned to devise a code in their language that would confuse and frustrate enemy listeners. Code words had to be short and easily learned and recalled. The men developed a two-part code. The first, a 26-letter phonetic alphabet using Navajo names for eighteen animals and other words for various letters: “zinc” (Z), “Ute” (U), “quiver” (Q), etc. The second part was a 211-word English vocabulary with Navajo synonyms: “Aircraft Carrier” (Bird Carrier), “Fighter Plane” (Hummingbird), etc. Conventional Marine Corps codes involved lengthy encoding and deciphering procedures using sophisticated electronic equipment. The Navajo code, relying on the sender’s and the receiver’s brains, mouths, and ears, was much faster.

Depending on pronunciation, a Navajo word can have four distinct meanings. In 1942, there was no Navajo alphabet. The language did not exist in written form. At government boarding schools to which Indian children were sent, teachers and administrators often forbade their charges from speaking Navajo or any other Indian language, demanding that they speak only English. Many Code Talkers attended boarding schools. As adults, they found it puzzling that the same government that had tried to take away their languages in schools later gave them a critical role speaking their languages in military service.


Introduce your students to the topic (read the background information on the Navajo Code Talkers to your students).

Split students into groups of at least 2 and pass out the Navajo Code Talkers Dictionary and Code Breaker Activity. Students will use the Navajo Dictionary to encrypt and decrypt various messages.

Go over the first page of the activity, describing to students how the code works. Work through the first encrypted message at the bottom of the page using the answer key. Have students use the decryption section of the Navajo Dictionary, as well as the appendix, to find the answers.

If you have extra time, have students create their own messages, and encrypt them using the Navajo Dictionary. Have students write 3 short messages on a separate piece of paper. Students will exchange papers with their partners, and decrypt each other’s messages.

Review the codes with the class.


  • Was it easier to code a message, or decode a message?
  • Why would people want to use a code?