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DHistory
History · Thornton

Thornton dates to 1956, and 1 of its places is on the National Register

More historic than 10% of U.S. towns · #120 of 159 in Colorado. What drives it

Most of Thornton was built recently: 0.3% of its homes predate 1940 and the median home dates from 1997. Its Register listing is the Eastlake Farmers Co-Operative Elevator Company. Below: maps from 1938 on and the census since 1960.

1956founded
1on the National Register
0.3%homes built before 1940
6famous people
Add an old photoShare a memory
Quick answers

How Thornton began

When was Thornton founded?

1956

Thornton dates its founding to 1956 (Wikidata). The census first counted it in 1960.

First census: 11,353 in 19602020 census: 141,86770 years

How historic is Thornton?

D

More historic than 10% of U.S. towns, on its age, its old homes and the National Register.

What drives the grade ↓
Founding year: Wikidata. First post office: 1912.The full story ↓
History grade

What drives Thornton’s History grade

On its age, its old homes and the National Register, Thornton is more historic than 10% of U.S. towns, #120 of 159 in Colorado. Its National Register listings hold the grade up; its age pulls it down.

D
HistoryA character grade: shown, never part of Thornton’s overall grade.
Founding era1956, from Wikidata: founded 1945 or later, an older era than 2% of U.S. townsD−Homes built before 19400.3% of homes (±0.2) · typical CO town 2.5% · U.S. 8.4%DNational Register1 listing, 0.1 per 10,000 residents · typical CO town 1.1 · U.S. 2.4B−
All U.S. towns we grade (21,289)Ahead of 10%
NewerOlder
Colorado towns of 2,500+ (159)Ahead of 25%

Among the 400 U.S. cities of 100,000 or more, Thornton ranks #377 on History.

Few Colorado towns list much on the Register (a typical Colorado town has 1.1 per 10,000 residents, the U.S. 2.4), so Thornton’s 0.1 sits near the middle of its state (45% of Colorado towns have fewer) while its 1 listings outnumber those of 51% of U.S. towns.

Newer cities are common at Thornton’s size: in the typical U.S. city of 100,000 or more, 5% of homes predate 1940.

How sure. Graded on any two of the three inputs instead, the letter would range from D− to C−. The pre-1940 share (±0.2 points) is firm at this size. Two sources give 1956.

Founding year: Wikidata (other dates in Quick answers). Homes: Census ACS 2020–24. National Register: National Park Service, May 2026 list; each listing counted once (boundary changes and added documentation belong to their listing), and a historic district counts its contributing buildings. How TownRatings grades history →

What stands out about Thornton’s past

Read from the archive, the National Register and the record. The page puts what stands out first.

A history waiting to be writtenNo old photos of Thornton are in the public archives yet. The rest are in attics and albums.
★ What stands out · Help out

Start Thornton’s collection

The first neighbors to add old photos shape how Thornton’s history is told.

Decades since 1900 with photos
00s10s20s30s40s50s60s70s80s90s
0 of 10 decades. The empty ones are waiting for someone’s album.
Share a family photoSign in to add one+10
The story

How Thornton came to be

From Wikipedia’s history of Thornton.

Read it all →

Thornton consisted solely of farmland until 1953, when Sam Hoffman purchased a lot off Washington Street about seven miles (11 km) north of Denver. The town he laid out was the first fully planned community in Adams County, and the first to offer full municipal services from a single tax levy, including recreation services and free trash pickup. Thornton was named in honor of then-incumbent Colorado Governor Dan Thornton.

The Thornton Community Association (TCA) was formed in 1954 to help guide the new community's development. By the end of 1955, Thornton had 5,500 residents in over 1,200 homes. The TCA was instrumental in Thornton's incorporation on June 12, 1956. Oyer G. Leary was elected the first mayor.

Text from Wikipedia, licensed CC BY-SA 4.0.

Timeline

Thornton, 1912 to 1991

Woven from the archive, old maps, post office records, the National Register and the people born here.

  1. 20th century
  2. 1912Post officeThe Eastlake post office opens
  3. 1938On the mapFirst mapped by the U.S. Geological Survey
  4. 1948Born hereEdward Casso is born here
  5. 1956
    FoundingThornton is established
  6. 1978Born hereAdrian Mora is born here
  7. 1988Born hereNikki Marshall is born here
  8. 1991Born hereJosh Bredl is born here
By decade

Thornton, decade by decade

Today17 recent
Thornton, Colorado2018Thornton, ColoradoThornton, Colorado2018Thornton, ColoradoSouth Platte River Near2018South Platte River NearCosta 000346 172260 517450 45782017Costa 000346 172260 517450 4578Commuter rail bridge construction, 88th Ave, 22016Commuter rail bridge construction, 88th Ave, 2Frogeye salad2015Frogeye saladColorado2015ColoradoColorado2015ColoradoThornton, CO, welcome sign IMG 52092010Thornton, CO, welcome sign IMG 5209Thornton Trail Winds sign2009Thornton Trail Winds signExit 226 to 144th Avenue, Interstate 252008Exit 226 to 144th Avenue, Interstate 25Exit 225 to 136th Avenue, Interstate 252008Exit 225 to 136th Avenue, Interstate 25Exit 223 to 120th Avenue (S.R. 128)2008Exit 223 to 120th Avenue (S.R. 128)Exit 221 to 104th Avenue, Interstate 252008Exit 221 to 104th Avenue, Interstate 25Exit 220 to Thornton Parkway, Interstate 252008Exit 220 to Thornton Parkway, Interstate 25US Navy 070508-N-0318S-001 Sailors stationed aboard Pre-commissioning Unit (PCU) Mesa Verde (LPD 19), talk to children …2007US Navy 070508-N-0318S-001 Sailors stationed aboard P…COMap-doton-Thornton2005COMap-doton-Thornton
On the map

Thornton on the map, 1938 to 1980

Every edition of the U.S. Geological Survey’s map of Thornton. Tap a year, or press play to watch the town change.

Thornton on the 1938 USGS mapThornton on the 1940 USGS mapThornton on the 1950 USGS mapThornton on the 1965 USGS mapThornton on the 1971 USGS mapThornton on the 1980 USGS map1938Derby sheet · 1:24,000

U.S. Geological Survey historical topographic maps (public domain), via Esri’s collection of the scans. The red ring marks the center of Thornton.

On the National Register

1 historic place in Thornton

The country’s official list of buildings and places worth saving.

place listed
1
National Historic Landmarks
0
none yet
historic buildings protected
1
each building in a district counts
first listed
2010
Eastlake Farmers Co-Operative Elevator Company
Eastlake Farmers Co-Operative Elevator Company
Structures
Eastlake Farmers Co-Operative Elevator CompanyStructure

National Park Service, National Register of Historic Places. Photos from Wikimedia Commons, credited on each place’s page.

People over time

Thornton, census by census

020,00040,00060,00080,000100,000120,000140,0001960198020002020141,867

Grew from 11,353 people in 1960 to 141,867 in 2020, more than tenfold.

7 censuses, 1960–2020.

U.S. Census Bureau decennial counts, from the census table on Thornton’s Wikipedia page.

Famous people

6 famous people were born in Thornton

Writers, athletes, leaders and more, ranked by how widely they’re known.

See all →
Nikki MarshallAmerican soccer player · b. 1988
J
Josh BredlAmerican professional wrestler · b. 1991
E
Edward CassoAmerican politician · b. 1948
A
Adrian MoraAmerican boxer · b. 1978
K
Kyle SleethAmerican baseball player · b. 1981
B
Billy GonzalesAmerican football player and coach · b. 1971
Places that used to be

Old corners, places now gone and burying grounds

Old hamlets and crossroads still carry their names on the map.

Hamlets and corners on the map
EastlakeQuimby
Gone or out of use
Colorado Consolidated Rock PitmineHoly Cross SchoolschoolHutton High SchoolschoolSunhealth Speciality Hospital For DenverhospitalWestern Paving Company Pitmine
1cemetery inside Thornton
Highland Memorial Gardens

US Post Offices dataset (Blevins & Helbock, CC0). Places and cemeteries from the USGS Geographic Names Information System (2021).

Stories next door

History across the town line

Each neighbor’s History grade, on the same three inputs.

Northglenn3 historic placesC−Todd CreekIts storyDWelbyIts storyD−Commerce City1 historic placeCSherrelwoodIts storyDBroomfield1 historic placeC−Federal HeightsIts storyD−Westminster6 historic placesC

Questions about Thornton’s history

What year was Thornton founded?

In 1956, according to Wikidata. Thornton’s post office opened in 1912, and the census of 1960 counted 11,353 people here.

How does Thornton rank for history?

Thornton is more historic than 10% of U.S. towns, #120 of 159 in Colorado. The History grade combines the town’s founding era, the share of homes built before 1940 and its National Register listings. It’s a character grade, so it isn’t part of the overall grade. How it works.

What is on the National Register in Thornton?

One place: the Eastlake Farmers Co-Operative Elevator Company (listed 2010).

How old are the homes in Thornton?

0.3% of Thornton’s homes were built before 1940 (Census estimate), against a typical 2.5% for a Colorado town; the median home was built in 1997.

Memory lane

What the archives can’t tell you, neighbors can.

Town Square →
Start a conversation
Sources

Where this page comes from

Founding dates: Wikidata, Wikipedia, the U.S. post office records of Blevins & Helbock (CC0) and the Census. Homes by year built: Census ACS 2020–24. National Register of Historic Places: National Park Service (list of May 22, 2026). Old photos, postcards and papers: Wikimedia Commons, the Library of Congress and other public archives, credited on each item’s page. Maps: U.S. Geological Survey historical topographic maps (via Esri) and Sanborn fire-insurance maps (Library of Congress). History text and census tables: Wikipedia (CC BY-SA 4.0). Places that used to be: USGS Geographic Names Information System (2021).

From Wikimedia Commons (17), the National Register of Historic Places (1), Wikipedia, Wikidata and Wikipedia for famous people, U.S. Geological Survey historical maps, U.S. Census counts (via Wikipedia), the US Post Offices dataset (Blevins & Helbock) and the USGS Geographic Names Information System. Archive images are copied here with their credits and licenses, shown on each photo’s page. Refreshed monthly.