SAN FRANCISCO - John "Marmaduke" Dawson, a longtime Grateful Dead collaborator who co-wrote "Friend of the Devil" and developed a devoted following with his psychedelic country group New Riders of the Purple Sage, has died. He was 64.

Dawson died Tuesday from stomach cancer in San Miguel de Allende, Mexico, where he had retired several years ago, said Rob Bleetstein, archivist for the band.

With the Grateful Dead's Jerry Garcia, Dawson co-founded New Riders in 1969 to showcase his songs along with Garcia's playing his pedal steel guitar.

Two other Dead members, bassist Phil Lesh and drummer Mickey Hart, also played in New Riders for a time.

The band toured with the Dead starting in 1970 and released eight albums on Columbia Records from 1971 to 1976.

Dawson also contributed to a number of Grateful Dead songs, most notably co-writing "Friend of the Devil" with Garcia and Dead lyricist Robert Hunter.

The New Riders scored their first gold record in 1973 with the hit "The Adventures of Panama Red."

In 1974, the band played to 50,000 fans at a free concert in New York's Central Park. *