Colorado

Jefferson

582,910

2020 population

1870

first census record

census records

About Jefferson

Jefferson, Colorado, first appears in the United States federal census in 1870, when it recorded a population of 2,390. At the most recent census, in 2020, its population stood at 582,910.

The county's recorded population has risen across the decades to its highest level in 2020.

On the ground today, 90 places are listed on the National Register of Historic Places.

Population by decade

Census Year	Population	Chart
2020	582,910
2010	534,543
2000	527,056
1990	438,430
1980	371,753
1970	233,031
1960	127,520
1950	55,687
1940	30,725
1930	21,810
1920	14,400
1910	14,231
1900	9,306
1890	8,450
1880	6,804
1870	2,390

Source

Population data from the United States decennial census, U.S. Census Bureau (public domain).

Historic places in Jefferson

National Register of Historic Places listings in Jefferson, Colorado.

Rio Grande Southern Railroad, Motor No. 6

Golden

Genesee Park

Golden

Evergreen Conference District

Evergreen

Coors, Herman, House

Golden

Lookout Mountain Park

Golden

Deaton Sculptured House

Golden

Hildebrande Ranch

Littleton

Red Rocks Park District

Loveland Building and Coors Building

Rio Grande Southern Railroad, Motor No. 2

Golden

Browse all Coloradohistoric sites ›

Other counties in Colorado

Explore census history and historic records for more Colorado counties.

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Everything a full report reveals about Jefferson County, Colorado

This page charts the census history of Jefferson County, Colorado. A full Aubrey report for an address here pulls together everything the historical record holds about the ground, from the earliest settlement to the twentieth century:

Overview

An interactive map of the location with historic sites, battles and Native heritage plotted, and its full story era by era.

The Land

The historic sites and place names around the location, and how this land was settled and used.

Geology

The bedrock beneath the site, its age and rock type, reaching back millions of years.

LiDAR Terrain

Laser-scanned terrain that reveals earthworks and old features hidden in the landscape.

Conflict & War

The battles, raids and skirmishes fought near here, across every era of American conflict.

The Civil War

The Civil War on this ground, 1861 to 1865: who held it, and the battles, camps and regiments nearby.

The Soldiers

The men who marched from here in the Civil War, named and traced where the record allows.

Native Heritage

The Native nations who held this land, mapped across time from before European contact to today.

Settlement

Who claimed and held this ground, from Indigenous homelands through the colonial powers to the United States.

The Community

How the town grew, who came, and what kind of place it became, traced through the census record.

Rivers & Rail

The rivers, canals and railroads that connected this place between 1830 and 1911.

Notable People

The people born, buried or genuinely tied to this exact place, with their stories.

Historical Maps

Historic maps of the location layered over how it looks today.

Finds & Access

Museum objects tied to the area, and the laws on searching, collecting and access here.

Literature

The old books, county histories and archives that mention this place, quoted with their sources.

Spotlight

A deep dive into the most remarkable, lesser-known history of the place, traced back to the record.

Points of Interest

The most significant historic sites and landmarks near the location, and why they matter.

Timeline

The whole story of the location told era by era, from first peoples to the present day.

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Coloradohistory ›NRHP historic sites ›Notable people from Colorado›

Frequently asked about Jefferson

When does Jefferson first appear in the US census?

Jefferson, Colorado first appears in the federal census in 1870, with a recorded population of 2,390.

What is the population of Jefferson?

At the most recent federal census (2020), Jefferson had a recorded population of 582,910.

How many historic places are in Jefferson?

90 sites are listed on the National Register of Historic Places in Jefferson, Colorado.

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