I am at San Quentin But Not in the Pen - Big Pig

Front:
am at San Quentin but not in the pen H. LE CANTE PUBLISHED FOR

Back:
Pot Message U.S.POSTAGE US.POSTAGE PR NT ONE ONE C BNT Mrs CA Mgeuhangan Cer Wi Werra CALIFORNIA SALES Co., PUB., SAN FRANCISCO arghche SAN