I am sorry, but I have a different take. The mountain bike was not invented in the 70's, or the 60's, or in Marin County, or by anybody currently living. It is just not true. It can't be. The REAL first mountain bike was invented well before the turn of the 20th century. Enter the very first bicycle - the wooden horse. Sans chain and sprocket transmission (which Leonardo invented back in the 12th century, but it never made it to a bike until the 750 yrs later), the wooden horse wasn't much more than a old school scooter the rider straddled and walked along. It operated the same we all did as kids after our chain broke a long way from home. The first bicycles must have been the first mountain bikes - there were no paved roads! OK, a beaten wagon trail does not a singletrack make, but let's get real for a second. You're telling me kids back then didn't sneak off with their dad's rig and push it to the top of the local hills and ride down - fast? You KNOW that happened and probably as often as they could get away with. And you know it turned into a race at some point. There was likely some serious ass-whooping when they got caught, but no doubt is was well worth the thrill. So my contention is, not only was the first mountain bike invented a long time ago, the first mountain bike was a DH rig. Nico would be proud!