To find location information, hours of operation and specific services such as passports and assistance with burial flags: Dial 1-800-ASK-USPS (800-275-8777) Visit www.usps.gov and look for Quick Tools in heading, drop down menu will provide the Find USPS Locations option, select and enter City and State or Zip code. There are many retail sites (grocery stores, drug stores) which offer some USPS services, such as mailing supplies, mail drop off or stamps.