I lived in Marin County, for many years.
I still have property there.
Gonzo. I learned that term from mountain bike enthusiasts there.
The fact is, riding a mountain bike at high speed off Mt. Tam is a big deal "sport" around there.
In Marin County, drugs are still a very big deal all the intervening years since the 1960's: from kids in middle school to aging hippies.
I would say "investigation" is called for, but drugs doesn't have to be the answer.
Many of the mountain bikers that come in to ride in Marin County are inconsiderate total jerks.