James William Guercio..... sometime bassist with the Beach Boys and legendary Producer of:
Chicago
Blood, Sweat & Tears
Carl Wilson
From Wikipedia:
Guercio was the founder of Caribou Ranch, a popular recording studio in Colorado's Rocky Mountains. The first true radio hit recorded at Caribou was Joe Walsh's "Rocky Mountain Way". In addition to Chicago (starting with Chicago VI), the studio has been used by numerous other artists: Elton John (for his Caribou album as well as "Captain Fantastic" and "Rock of the Westies"), Billy Joel, Rod Stewart, Carole King, Stephen Stills, Waylon Jennings and Supertramp