Slides occur inland as well as near the coast. You can see evidence of slides several places along the Pine Ridge trail. If the ground is covered by loose rock, it's an indication of frequent slides (at least frequent enough that soil hasn't had a chance to form on top of the rocks). Another indication is the lack of vegetation: you may see large trees that have survived slides and new growth that has grown since the most recent slide, but intermediate sized trees will be absent. (Fires can also wipe out vegetation, but you'd then see signs of the fire, like redwood trees with blackened trunks.)
Still, it's very unlikely that you would get hit by a slide hiking along a trail (or driving on Highway 1). If you hike during a storm, you could get cut off by a slide, but you're probably more likely to get stranded by a swollen stream.
