This cache can help with several challenges. Rhyme Time Challenge, California Multi Cache Challenge, and maybe more.
This is a simple 2 stage multi. GZ should take you to a large blue sign with a 10 digit phone number and a 3 digit penalty amount for not complying. Add the 10 digits of the phone number together to get X. Add the 3 digits of the "fine" together to get Y.
N = X*Y+351 and W = ((X-Y)*14-4)/2
The final is at N38 00.N and W122 16.W.
Check sum for all digits is 55