Although Marin landscape artist Daniel McCormick often exhibits his works of earth art in galleries, the natural place for his organic sculptures is in the wild, where the graceful forms find a home clinging to the edges of creek banks and gullies, gradually subsuming themselves into the existing environment. Spark follows McCormick as he works on an installation in the John West Fork of Olema Creek, in Marin -- a prime spawning ground for endangered coho salmon and steelhead trout.