Alta Loma Post Office

6649 Amethyst Ave, Rancho Cucamonga, CA 91701

Contact Numbers

Phone: 909-987-0785
Fax: 909-987-3653
TTY: 877-889-2457
Toll-Free: 1-800-Ask-USPS® (275-8777)

Lobby Hours
PO Box Access Available

Monday 8:30am - 5:00pm
Tuesday 8:30am - 5:00pm
Wednesday 8:30am - 5:00pm
Thursday 8:30am - 5:00pm
Friday 8:30am - 5:00pm
Saturday Closed
Sunday Closed

Last Collection Times

Monday 4:00pm
Tuesday 4:00pm
Wednesday 4:00pm
Thursday 4:00pm
Friday 4:00pm
Saturday 3:00pm
Sunday Closed

*This facility does not process US Passports applications or renewals. Check nearby locations below.

  • Business Line
  • Packaged Stamps
  • Pickup Accountable Mail
  • Pickup Hold Mail
  • PO Box Online
  • Lot Parking

Visit our Links Page for Holiday Schedule, Change of Address, Hold Mail/Stop Delivery, PO Box rentals and fees, and Available Jobs.

*Please call to verify information. Is anything incorrect? Let us know here

Nearby Post Offices:

Rancho Cucamonga
10950 Arrow Rte
1.9 miles away

333 E Arrow Hwy
2.4 miles away

323 N Turner Ave
2.8 miles away

1555 E Holt Blvd
2.9 miles away


*Comments below are not read by postal employees. Please do not post personal information.

*By clicking Submit, you agree to our Privacy Policy & Terms of Use.


Small office. Usually one clerk. The line can get long especially when people don’t have their mail or pkgs ready. Please DO NOT park or hover, idle, etc in the BLUE HANDICAP SPACE if YOU don’t have a Handicap placard. It’s a hefty fine!!! And we all have cell phone cameras!!


on 7/14/2021 at 9853 Mignonette Street , Rancho Cucamonga, California 91701 USA, my mail carrier left time sensitive outgoing mail in my home mail box. They DID deliver my personal mail, but DID NOT COLLECT THE TIME SENSITIVE OUT GOING MAIL!! I'm sorry, but I find this to be UNACCEPTABLE!! If they can put mail IN...they can take mail OUT, and that there is exactly what I expect from my mail carrier...NO LAGGIN'!!!!! Thank You


Be advised USPS as of 08NOV14 - carriers who sub for reg delivery person are stopping by only to collect mail as flagged but they have demonstrated over the past three days to not deliver anything. Is this the new standard? Where are my bills that normally come? They pull into the cul de sac, eval the flags, then scoot.

* is not a part of, or affiliated with, the official United States Postal Service (USPS).