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ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — ZIP/80109

80109

ZIP 80109 is in Castle Rock, Colorado, in Douglas County; Mountain time. Castle Rock has 3 ZIP codes; the others are 80104 and 80108.

Type
Standard
Time zone
America/Denver
County
Douglas
Population
28,400
Coordinates
39.3723, -104.9121
☼ Live from 80109 — Castle Rock, CO

Weather right now

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Local time: —

Where 80109 is

Approximate ZIP boundary (Census ZCTA 2020). ZIP codes are mail routes, not areas, so the shape shown is the Census tabulation area that approximates it.

★ Weird and wonderful facts about 80109
  • 🔢 Type 80109 into a pocket calculator and turn it upside down: GOIOB — not quite a word, sorry.
  • ➕ As a number, 80,109 = 3 × 3 × 3 × 3 × 23 × 43. Its digits add up to 18, a total 2,332 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 10011100011101101
  • 🏠 Its numerical neighbours: 80108 (Castle Rock, CO, 6 mi away) and 80110 (Englewood, CO, 20 mi away).
  • 🔄 Backwards, 80109 becomes 90108, which is not a ZIP code at all.
  • 👥 31 other ZIP codes are made of exactly the same digits (00918, 00981, 01089, 01098, 01890, 01908, …). The farthest-flung twin is 09810 in APO AE, a military post office, 7,139 miles away.
  • 🧭 Farther north than 51% of all ZIP codes, and farther west than 83%.
  • 🎯339 miles west of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 80109 and you would come out at 39.37°S, 75.09°E — 730 miles from Port-aux-Français, French Southern Territories, the nearest big city to that spot.
  • ☀Longest day of the year: 14h 57m of daylight. Shortest: 9h 23m.
  • 📏 At 26.0 square miles of land, 80109 is bigger than 43% of ZIP codes — room for about 20 Central Parks.
🌙 The sky over 80109 today
  • Working out the sun…
🌋 Shake report
  • Checking the USGS…

Source: USGS.

People and housing

Population28,400This ZIP28,400
Households9,728This ZIP9,728
Housing units9,873This ZIP9,873
Median age36.9This ZIP36.9Colorado37.7US 38.9
Median household income$155,025This ZIP$155,025Colorado$95,470US $80,734
Median home value$675,500This ZIP$675,500Colorado$539,400US $332,700
Median gross rent$2,304This ZIP$2,304Colorado$1,761US $1,413
Bachelor's degree or higher57.8%This ZIP57.8%
Mean commute26.8 minThis ZIP26.8 min
Population density1,092.8 / sq miThis ZIP1,092.8 / sq mi

Business and tax activity

Business establishments644This ZIP644
Employees5,224This ZIP5,224
Annual payroll$290,812,000This ZIP$290,812,000
Tax returns filed13,010This ZIP13,010
Total adjusted gross income$1,740,183,000This ZIP$1,740,183,000

Land area

Land area25.99 sq miThis ZIP25.99 sq mi
Water area0.01 sq miThis ZIP0.01 sq mi

Other place names in 80109

Census places whose land this ZIP code overlaps. The Postal Service may accept other city names in an address, too.

ZIP codes near 80109

ZIPCityDistance
80163 Littleton, CO 4.7 mi
80108 Castle Rock, CO 5.9 mi
80104 Castle Rock, CO 6.9 mi
80131 Louviers, CO 8.9 mi
80134 Parker, CO 10.4 mi
80130 Littleton, CO 10.8 mi
80124 Lone Tree, CO 11.1 mi
80125 Littleton, CO 11.2 mi
80116 Franktown, CO 11.4 mi
80126 Littleton, CO 12.0 mi

Find every ZIP code within 10 miles of 80109 →

Questions about this ZIP code

Where is ZIP code 80109?

80109 is in Castle Rock, Colorado, in Douglas County, part of the Denver-Aurora-Centennial, CO metropolitan area. Its published point location is 39.3723, -104.9121.

What county is 80109 in?

80109 lies in Douglas County.

What time zone is 80109 in?

80109 uses America/Denver.

How many people live in 80109?

About 28,400 people live in ZIP code 80109, in 9,728 households, at 1,092.8 people per square mile. These are American Community Survey 5-year estimates for the ZIP Code Tabulation Area, not a headcount.

What is the median household income in 80109?

$155,025 a year, against $95,470 across Colorado.

What ZIP codes are near 80109?

The closest are 80163 (4.7 mi), 80108 (5.9 mi), 80104 (6.9 mi), 80131 (8.9 mi) and 80134 (10.4 mi).

Is 80109 a PO Box ZIP code?

80109 is a standard ZIP code. A normal ZIP code with street delivery.

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Cite this page

zipcodes.pro. “80109 ZIP Code — Castle Rock, Colorado (Douglas County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/80109

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