This geocache is in EBMUD lands. You'll need an EBMUD hiking permit to walk in this area, and these are easy to get, it will take you just a couple minutes online. Go here to do that: https://www.ebmud.com/recreation/buy-trail-permit/
Start the geocache quest in the Tilden Park Inspiration Point parking lot, head north from the Inspiration point trail near restrooms to the EBMUD lands gate. NOTE: If you try to enter this area from any other point other than the designated EBMUD trailhead, you will see NO TRESPASSING signage. These signs do NOT mean no one can hike here, as should be clear from the fact that there are trailheads and a whole series of public trails in the area. These signs are confusing but the point of them is that the general public is not allowed in, only those with permits, and you are supposed to enter via the trailheads.
As you head out along the northward trail, the first quarter mile of the trail is muddy in rainy season (now). After that it is less muddy.
Cache is at base of a trail post. 