I thought it may be:
Huntington Park Casino
6611 S. Alameda St.
Huntington Park, Ca
1984-1997

I was basing this on Larry Eastman's book, P. 91 where he shows a similar but different HPC monogram. Larry's is a no denom but the main reason that I think that your chip is not Huntington Park is that Larry's mold is large key.

Small key molds would not have been used in 1984....unless B.C. Wills used old stock. Any opinions from other Cal. card room collectors?