The trails in the Wilder Ranch backcountry generally stick to the open grasslands, which is why Wilder has such amazing views, but the "middle" section in a little patch of forest is one of my favorite areas. It's a little bit spooky with weird old stuff to discover. There are two old rock walls in this area that you can see from the trail, and if you look on the satellite map, you can see several more little bits of wall that you can't see from the trail. I remember a cache at one of the walls years ago, but it's been archived. I placed a new one next to the trail that doesn't require going near any of the walls.
You're looking for a small-to-medium container hidden next to the Long Meadow Trail. Most of the surrounding area is pretty scrubby with no really good spots to hide a cache, so hopefully the cache location should stand out.
Wilder Ranch is open from 8:00am to sunset daily. Dogs are not allowed, but bicyles are. Note that these backcountry trails are subject to closure after significant rain. Check the Wilder Ranch website for any closure information.
Happy hunting!