"It's not really that I'm all that great at doing it, but I'm a perfectionist," say Mattson. His Multnomah Falls took him a year to build, over the course of which he rebuilt the base five times. He estimates the sculpture probably took around 100,000 pieces to build. "I don't even know how to begin to count," he says. "Other than take it apart, and I may never take it apart." (Fragments of the sculpture are in storage boxes at Mattson's house.)