I was trying to think of a name for this one, and then realized that with the Indianapolis 500 running tomorrow, I didn't have to think too hard. The cache is just past the end of the white horse trail fence. You're looking for a pill container, wired low and covered with a geopile. There's no camo tape on the container right now, so the geopile is providing the camo; please take the time to restack the rocks so that the cache is not visible.
Parking for 6 or so cars is available at the Casino Ridge Staging Area; the residential streets past the Staging Area are private roads, so DO NOT PARK ON THEM! The horse trail from the staging area leads right up the hill to the cache (and then on into Chino Hills State Park).