From Discogs.com : "G*Park is the musique concrète project of Marc Zeier (b. 1954 in Jersey City, USA, relocating to Switzerland in 1961). Active since the early 1980s, although not prolific with recorded work, Zeier has also worked in video and with installations."
"Yack Park" was released by Zabriskie Point in 1993.
Get it here : G*Park - Yack Park