In another communication Colonel Dodge is still more definite: 

“The Plains Indians themselves believe the sign language was invented by the Kiowas, who holding an intermediate position between the Comanches, Tonkaways, Lipans, and other inhabitants of the vast plains of Texas, and the Pawnees, Sioux, Blackfeet, and other northern tribes, were the general go-betweens, trading with all, making peace or war with or for any or all.  It is certain that the Kiowas are at present more universally proficient in this language than any other Plains tribe.  It is also certain that the tribes farthest away from them and with whom they have least intercourse use it with least facility.”

Dr. William H. Corbusier, assistant surgeon United States Army, a valued contributor, gives information as follows: 

“The traditions of the Indians point toward the south as the direction from which the sign language came.  They refer to the time when they did not use it; and each tribe say they learned it from those south of them.  The Comanches, who acquired it in Mexico, taught it to the Arapahoes and Kiowas, and from these the Cheyennes learned it.  The Sioux say that they had no knowledge of it before they crossed the Missouri River and came in contact with the Cheyennes, but have quite recently learned it from them.  It would thus appear that the Plains Indians did not invent it, but finding it adapted to their wants adopted it as a convenient means of communicating with those whose language they did not understand, and it rapidly spread from tribe to tribe over the Plains.  As the sign language came from Mexico, the Spaniards suggest themselves as the introducers of it on this continent.  They are adepts in the use of signs.  Cortez as he marched through Mexico would naturally have resorted to signs in communicating with the numerous tribes with which he came in contract.  Finding them very necessary, one sign after another would suggest itself and be adopted by Spaniards and Indians, and, as the former advanced, one tribe after another would learn to use them.  The Indians on the Plains, finding them so useful, preserved them and each tribe modified them to suit their convenience, but the signs remained essentially the same.  The Shoshones took the sign language with them as they moved northwest, and a few of the Piutes may have learned it from them, but the Piutes as a tribe do not use it.”

Mr. Ben.  Clarke, the respected and skillful interpreter at Fort Reno writes to the same general effect: 

“The Cheyennes think that the sign language used by the Cheyennes, Arapahoes, Ogallala and Brule Sioux, Kiowas, and Comanches originated with the Kiowas.  It is a tradition that, many years ago, when the Northern Indians were still without horses, the Kiowas often raided among the Mexican Indians and captured droves of horses on these trips.  The Northern Plains Indians used to journey to them and trade for horses.  The Kiowas were already proficient in signs, and the others learned from them.  It was the journeying to the South that finally divided the Cheyennes, making the Northern and Southern Cheyennes.  The same may be said of the Arapahoes.  That the Kiowas were the first sign talkers is only a tradition, but as a tribe they are now considered to be the best or most thorough of the Plains Indians.”