Started as a way to lift the city 's spirits after the disastrous 1906 San Francisco earthquake , it has been run for more consecutive years over a given course and length than has any other footrace in the world ; although other footraces are older and have been run for more consecutive years , their courses and lengths have changed over time . During World War II participation sometimes slipped below 50 registrants , but the tradition carried on . With 110,000 participants , the Bay to Breakers race held on May 18 , 1986 was recognized by the Guinness Book of World Records as the world 's largest footrace . That record number was partly the product of the running boom of the 1980s ; currently the average participation is between 70,000 and 80,000 . Many participants do not register , of the estimated 60,000 participants in 2008 , 33,000 were registered . The '' San Francisco Examiner , '' a former sponsor of the race , published a list of the first 10,000 finishers the day after the race each year
1906 San Francisco earthquake
1906 San Francisco earthquake
Bay to Breakers