While the Navaho code talkers are more well known other Native American tribes also served in that role including the Lakota. There should be a monument in Washington DC honoring all the code talkers in both WW-I and WW-II. It would be especially fitting to honor those Native Americans serving in this role in WW-I as at the time they were not considered US citizens.
I don’t know which Army code talkers of WWI were citizens or not, but Indians have been becoming citizens since 1831, so who knows about those individuals?