Main Altadena Post Office
2271 Lake Ave., Altadena 91001
https://www.usps.com/
Zip Look Up
https://tools.usps.com/go/ZipLookupAction_input
USPS Postal Collection Boxes
mailboxlocate.com/states/CA/cities/ALTADENA
U.S. Postal Annex
Webster Pharmacy
https://www.websterspharm.com/
2333 N Lake Ave., Altadena 91001
626 797-1163