The Navajo Nation said he died Wednesday of heart complications.

Billison joined a group of Navajo Marines -- the Code Talkers -- who invented a military code based on the Navajo language to confound the Japanese during World War II. They used the code and their native language to communicate troop movements and orders.

Billison, 79, was born in a hogan in Ganado, Ariz., and came from a traditional family, family members said Wednesday. Billison, a medicine man's son, graduated from Albuquerque Indian School and obtained his associate of arts degree from Bacone College in Bacone, Okla, his son, Samuel Billison Jr. said. He earned his doctorate of education from the University of Arizona. Billison has the distinction of being the first Navajo of the Navajo Code Talkers to earn a doctorate degree.

Billison was a certified K-12 teacher, principal and superintendent. He helped educate thousands of Navajo students throughout Oklahoma, Texas, New Mexico and Arizona.

Billison served on the Navajo Nation Council for two terms representing his home chapter of Kinlichee, Ariz.

"Most notably, Dr. Billison was president of the Navajo Code Talkers Association. He served in the United States Marine Corps, Reconnaissance Company, 5th Marine Division, and participated in the capture of Iwo Jima," Samuel Billison Jr. said. (Marine Corps link)

"He also served in the Occupational Forces in Japan after WW II. He has been instrumental in obtaining national recognition of the Navajo Code Talkers and has traveled widely on their behalf making presentations to various organizations on how the code was developed and used during World War II. He even provided the voice for the limited edition GI Joe Code Talker action figure and donated all the proceeds he received to the Navajo Code Talker's Association," Samuel Billison Jr. said.

Dr. Billison is survived by his wife, Patsy Billison, five sons and seven grandchildren.

"It saddens me to hear of the untimely and sudden death of Dr. Billison. He was a maternal grandfather to me. Dr. Billison was a hero to the Navajo, as to the world, because he was Navajo Code Talker. He was also a very honorable leader of his community and his nation. Certainly he will be sorely missed. As we pay last respects I ask all Navajo to pay homage to all his accomplishments for our people and pay homage to his family, who were his roots and his strength.

"Dr. Billison's legacy is forever secured in his contribution to the world as a Navajo Code Talker. The Code Talkers are known throughout the world for their bravery and courage. Dr. Billison traveled to various parts of the world to carry the important message that the Navajo Americans offered their language to allow the citizens of the United States the freedom that we are able to enjoy today," Navajo Nation President Joe Shirley said Wednesday.

Former Navajo President Albert Hale echoed Shirley's sentiments.

"It's a great loss not only to the family but to the nation as a whole, especially for the Code Talkers. He was an advocate for them and I'm sure they'll miss that leadership. He was always very support to me and even when I was the Navajo Nation president, the support was there. He called me his nephew, because of the clan relationship and I've always been honored to have him call me that," Hale, now an Arizona state senator, said.

"The entire Navajo Nation is deeply saddened by the loss of one of our heroes and leaders. We are grateful for the service he provided in using the Navajo language during World War II, that helped the United States government in their efforts to end the war," said Maxine Etter, spokeswoman for Navajo Nation Vice President Frank Dayish Jr., who is a former Marine.

Leo Chischilly, director of the Navajo Nation Veteran Affairs Office and a close friend, expressed shock at the news.

"I got the news this morning that Dr. Billison had passed on. It was very shocking because the last time I saw him, he was in good spirits and looked healthy. That was at installation of Navajo Code Talker memorial statue in Window Rock, the Navajo Nation Capital. I knew him for a long time and we use to talk on the phone. There were times when students would ask for a Navajo Code Talker to speak and I would call him and he would go and share his experience. He served his country and was well-known nationally and internationally. He was a great man and I'm very sad about his passing," Chischilly said.

Did you know? (Facts about the Navajo) ~ The Yei-bi-chi Dance [as originally performed, this 'cornmeal scattering dance ritual' was physically impassioned, lavish, and extravagant. The dancers leaped and cavorted, invoking the powers of the Spirit on behalf of the people.] For more (House Blessing Ritual - thanks to Michelle!)

Monument Valley [Navajo Tribal Park] within the Navajo Nation provides perhaps the most enduring and definitive images of the American West. The isolated red mesas and buttes surrounded by empty, sandy desert have been filmed and photographed countless times over the years for movies, adverts and holiday brochures. Because of this, the area may seem quite familiar, even on a first visit, but it is soon evident that the natural colours really are as bright and deep as those in all the pictures. The valley is not a valley in the conventional sense, but rather a wide flat, sometimes desolate landscape, interrupted by the crumbling formations rising hundreds of feet into the air, the last remnants of the sandstone layers that once covered the entire region. See Shonie De La Rosa`s Navajo site.

Navajo relations with the Belinka - white man - have been a mixed bag for the Navajo People. Once enemies, now friends, the off and on again symbiosis has suffered from past suspicions and official animosities. Economically, culturally, and historically, Navajo society is intertwined with that of mainstream America. The challenge of contemporary Navajo culture is how to maintain a balance of inclusion, with the preservation of the most valued character of Diné distinctiveness and continuity with the revered past.