Marin County, CAlifornia the birth of a sport

Marin County is the birthplace of the Mountain Bike. Back in the early 1970s a group of young men and women started riding their Klunker paperboy bikes up and down the fire protection roads in the county.  While some would argue they weren't the only (or even first ones) to start taking bikes up and down mountains, it was their modification of their cruiser bikes, adding of handbrakes and eventually derailleur and multiple gears that get them credit with the birth of the sport. Come ride the birthplace with mountain Bike SF.