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Zip Code 80109 — Castle Rock, CO

ZIP Code 80109 is associated with Castle Rock, CO, in Douglas County. The listed population estimate is 28,400; estimated density is 421.9 people per square mile. Among records with population estimates, it ranks #7 of 14 in Douglas County and #87 of 512 in CO.
Page generated: 2026-10-08. This is not the source data release date.

📍 View location on OpenStreetMap (39.364730, -104.900560)

Data MetricLocal Statistic
Postal / Zip Code80109
Primary CityCastle Rock
State / ProvinceCO
CountyDouglas
Total Population28,400
Population Density421.9 people/sq mi
TimezoneAmerica/Denver

How 80109 Compares

MetricZIP 80109Douglas County recordsCO records
Population estimate28,400373,996 (sum)5,862,421 (sum)
Population Density421.9 /sq mi----
County population rank#7 of 14----
State population rank#87 of 512----

Regional sums combine the population estimates in the listed ZIP records; they are not official county or state population totals.

Explore More ZIP Codes

Nearby ZIP Codes in CO

ZIP CodeCityDistancePopulation estimate
ZIP 80108Castle Rock6.1 mi36,730
ZIP 80104Castle Rock6.1 mi38,479
ZIP 80131Louviers9.6 mi276
ZIP 80134Parker10.4 mi80,302
ZIP 80116Franktown10.5 mi5,132

Data Sources & Methodology: Geographic coordinates and ZIP Code assignments are derived from underlying geographic and postal datasets. Note that ZIP Codes are USPS postal delivery areas, while Census ZCTAs are statistical approximation areas. Read full methodology →