Oldest ZIP codes in St. Clair County, MO

These are the 6 ZIP codes in St. Clair County with the highest median age, out of 6 with at least 1,000 residents. 64740 (Deepwater, 59.0), 64776 (Osceola, 49.6) and 64738 (Collins, 43.5) lead the list. There is no single "best" ZIP code in St. Clair County; the right one depends on who you want to reach, so the same ZIP codes are ranked several ways below.

Oldest ZIP codes in St. Clair County

RankZIPMailing cityMedian ageResidentsHouseholdsResidential mailboxes
164740Deepwater59.0 ±5.11,469677949
264776Osceola49.6 ±5.73,3741,4861,882
364738Collins43.5 ±7.01,368529569
464744El Dorado Springs43.1 ±4.68,2423,3493,275
564724Appleton City42.5 ±4.41,999821809
664763Lowry City41.5 ±6.61,676667—

How we ranked them

Ranked by median age of all residents, highest first (ACS 5-year estimates, 2020–2024). ZIP codes need at least 1,000 residents to be ranked; 6 of 12 qualify.

Which of these to mail, and why

Older ZIP codes respond to health care, hearing and vision, Medicare plans, home safety, estate planning and services that come to the door.

The top five ZIP codes on this list hold 6,862 households, on 20 carrier routes with 7,484 residential mailboxes. Open any of them on the route map to see each carrier route's own figures before you choose.

Open 64740 on the EDDM route map

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Businesses that mail these ZIP codes

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Frequently asked questions

Which ZIP code in St. Clair County has the highest median age?
64740 (Deepwater), at 59.0 (±5.1), among 6 ZIP codes with at least 1,000 residents.
How is this ranking calculated?
Ranked by median age of all residents, highest first (ACS 5-year estimates, 2020–2024).
Why are some ZIP codes missing?
ZIP codes with fewer than 1,000 residents are left out because their survey estimates swing too much to rank, and so are ZIP codes where the Census Bureau did not publish this figure.

This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.