Go east from the XC ski stadium area on Pincusion Mountain Loop (ski trail). After roughtly 3/4 of a mile, turn north off of the ski trail onto singletrack.
Review: Very fun trail - fairly well marked, and lots of diversity. Fluvian trail is an absolute blast. Lots of new trails as well. I'd recommend the Tilt-a-whirl trail if you come across it. Great trail!