This is the untouched world holding said Tri-River Canyon

Its basically a place where 2 rivers meet, 1 flows down 4 Z levels or so into the other, with a nice triangle of water at the bottom, and then they both flow off together happily ever after. Its also full of carp, aligators, hippos, and flying lungfish

pictures: http://imgur.com/a/mzCSF#0

I used the mayday tile set

The world has had one previous embark that failed miserably, i tried to face an aquifer after skimming the wiki somehow my dorfs got sucked into the pumps, maybe you can do better if you can re-embark?