County facts · Land area · October 22, 2026

Largest Counties in Colorado by Area and Population

The largest Colorado counties by land area and by 2023 population, plus the smallest, county seats and a link to each official parcel map.

Looking for the largest counties in Colorado? Colorado has 64 counties covering about 103,637 square miles of land, based on the Census Bureau's 2020 Gazetteer. The largest by land area is Las Animas County, at about 4,773 square miles, roughly 145 times the size of the smallest, Broomfield County (33 sq mi). Measured by people instead, the largest is El Paso County, with about 744,215 residents in the Census Bureau's July 1, 2023 estimate.

Each table below links the county's Platbookmapper page and its official parcel viewer, so you can go straight from the numbers to the property lines.

Colorado counties at a glance

• Counties: 64
• Land area: about 103,637 sq mi, plus about 458 sq mi of water inside county lines
• Residents, 2023 estimates: about 5,877,610, or about 57 people per square mile of land
• Median county land area: about 1,431 sq mi
• With a verified public parcel viewer in our directory: 58 of 64 (12 of them through a statewide viewer)

The 10 largest Colorado counties by land area

Together these 10 cover about 33% of Colorado's land area and hold about 17% of its residents.

The 10 most populous Colorado counties

These 10 hold about 82% of Colorado's residents in the 2023 estimates.

The 5 smallest Colorado counties by land area

A dash in the Seat column means Wikidata lists no current county seat for that county.

Most and least crowded

• Most people per square mile: Denver County, about 4,681 (then Broomfield County, 2,331, and Arapahoe County, 822)
• Fewest people per square mile: Hinsdale County, about 0.7 (then Kiowa County, 0.8, and Jackson County, 0.8)

Counties with the most water

The Census Bureau reports water separately from land. It counts lakes, reservoirs, rivers and, along a coast or a Great Lake, the water inside the boundary.

• Larimer County: about 38 sq mi of water, 1% of its total area
• Weld County: about 32 sq mi of water, 1% of its total area
• Bent County: about 28 sq mi of water, 2% of its total area

Using these numbers in a land search

• Land area is not parcel count. A large rural county can hold fewer parcels than a small suburban one, so size alone says little about how busy its parcel map is.
• Search, don't scroll. In a big county, type an address, owner name or parcel number into the viewer's search box, where it has one, instead of panning across the map.
• Records follow the county line. Deeds, plats and tax bills are kept by the county where the parcel sits, so a tract that crosses a county line usually has a parcel number on each side.
• Rounded figures. Land and water areas are rounded to whole square miles (one decimal for very small places). People per square mile is the 2023 estimate divided by land area.

Related guides

• Colorado county GIS websites by viewer
• Colorado plat maps
• Colorado parcel map guide
• Colorado landowner maps for hunting
• Colorado–New Mexico border counties
• Colorado–Utah border counties
• Largest county in each state
• Largest counties in the US by land area

More: All Colorado counties on Platbookmapper

Sources

• U.S. Census Bureau Gazetteer files, 2020 county land and water area.
• U.S. Census Bureau, Population Estimates Program, county totals, Vintage 2023 (July 1, 2023 estimates)
• Platbookmapper county GIS directory (live data file behind our county pages, pulled October 22, 2026) for each official parcel viewer.
• County seats: Wikidata (county seat property), cross-checked against Census place names.