The Blue trail is easily accessible, is great for hiking/biking, and has some great views across the lake.
Here are links to the official park site & to a trail map:
http://www.mercercountyparks.org/parks/mercer-county-park
http://www.jorba.org/sites/default/files/2010_SMART_trail_map_0.jpg
I placed this one just so I could provide a link to this classic children's toon from Ren & Stimpy. Oh Yeah!!!
http://youtu.be/RTrAVpK9blw
Should be pretty easy to find. It's next to that thing referred to in the song. What was it called again?
Now that I think about it, I probably should have used that song for cache #2 & 9. Oh well. Don't want to make things too easy for you.
Pen not included.
ENJOY!!