Living here in the Panhandle of Texas, Red River is said to originate with Prariedog Town Fork which starts between Amarillo and Canyon and runs through Palo Duro Canyon. I have also heard that Red River begins where Prariedog Town Fork and North Fork of Red River merge which would be North of Vernon, Tx. and east of the Altus, Ok and Vernon highway. I do know for a fact that the bridge on that highway says that is Red River, so I don't know where the official beginning of Red River is. The main tributaries and where they begin are: Prarie Dog Town Fork, just southwest of Amarillo Salt Fork, East Southeast of Amarillo, south of I-40 in Carson County Mulberry Creek, Ssoutheast of Amarillo, Armstrong County North Fork, Southeast of Pampa in Gray County I guess you can take your pick of which one is the actual beginning, since they all begin and merge within about 250 miles. Hope this clears up things for you. Pat Kunkel Amarillo, Tx Rains, Drake, Bridges, Valentine Smith