How about "Indus"? It's a major river that runs through China, India, and Pakistan. Nearly 2,000 miles long. Not the longest in the world, but an extremely important river nonetheless, having provided life for some of the largest human habitations of the ancient world.
I agree, the Indus is a great choice, being one of the major rivers of civilization. I like how long this thread has been going on. Who knew we were all so much into geography
