Lang was not among the producers of the December 6, 1969, Altamont Free Concert which some had billed as a "Woodstock West", but was asked by the Rolling Stones and Grateful Dead to assist with the last-moment re-location, from Sears Point Raceway to the Altamont Speedway, near Tracy, California. The concert was initially planned for Golden Gate Park, and was to feature The Rolling Stones, Grateful Dead, Santana, Jefferson Airplane, The Flying Burrito Brothers, and Crosby, Stills, Nash & Young. The City of San Francisco revoked the permits for the Golden Gate venue, ostensibly due to a San Francisco 49ers football game at Kezar Stadium, located in the park, on the scheduled date. The concert was subsequently moved to Sears Point Raceway. However, a dispute over film rights led to its cancellation. Lang and Grateful Dead manager Rock Scully were then offered the Altamont Speedway – a rival to Sears Point Raceway – by owner Dick Carter. After the venue was set for the concert, Lang appeared, with his experience in moving the much larger Woodstock festival. The venue was moved on December 4 to the racetrack with the concert starting December 6.