Tom, sorry I wasn't able to post sooner before you dumped your FSX install.Now that's interesting. I wish I had seen this BEFORE I sent my install to the grave.
I wonder if I just need to add UTX to get the river there?
Well, I guess I'll find out after I take on reinstalling everything later today.
Thanks for the help everyone. I'll let you know what happens.

My FSX is a brand-new install since March with SP2 and Acceleration. Me thinks MS just didn't put the river in. And you're right, it's there in FS9 although the mouth is strangely land-locked by a coastline glitch.