This piece is titled Maori Column and is by Alan Shepp. It was done in 1985.
Shepp, along with his artist wife, lives in Napa California. He has a BFA from the Cleveland Institute of Art, and an MFA from the University of Washington.
He is a multimedia artist who creates large scale sculpture and public art.
There is not a lot of information out there, either about this artist or this piece, but his website has some really gorgeous work on it.