For example, the hills around Almaden Valley and Santa Cruz mountain foothills are full of deer which are known positive carriers of Lyme Disease. In the 1990's, there were or are signs on the trails indicating this. I believe the same caution applies to hills extending towards San Francisco, which includes walking The Dish at Stanford.

Needless to say: wear long socks and have someone else completely check all of your limbs and back under bright light and magnification for those very tiny deer ticks.