Castle Rock history: the county seat by the butte, a stone depot, the star on the Rock, and a town of 741 that became 73,158

Castle Rock is the seat of Douglas County and, at the 2020 census, a town of 73,158 people. It is named for the castle-shaped butte near the middle of town, and for most of its first century it was small: the census found 741 people here in 1950. This is the short version of how it got from one to the other, from the town’s historical society, the county, the state’s census records and the other sources listed at the foot. Where they disagree, both are given.

A county seat, 1874

Douglas County is older than the town. It was one of the 17 original counties of Colorado Territory, created on November 1, 1861, and named for Senator Stephen A. Douglas of Illinois. Wikipedia’s county history has its seat at Franktown first, then at California Ranch from 1863, and at Castle Rock from 1874, the year most of the county’s eastern part, which had run to the Kansas line, became Elbert County. The Castle Rock Historical Society tells it the same way: in 1874 Castle Rock was designated the county seat of the newly realigned Douglas County. Wikipedia adds that it was chosen for its central location.

White settlers had come for rumors of gold and for land opened by the Homestead Act of 1862, but in Wikipedia’s account it was rhyolite, a volcanic building stone, and not gold that settled the place. One of the first homesteaders near the butte was Jeremiah Gould, who owned about 160 acres south of the Rock. In 1874 he gave 120 acres to the new town. Six streets were laid out and named Elbert, Jerry, Wilcox, Perry, Castle and Front, a courthouse square was set aside, and about 77 lots, each 50 by 112 feet, were auctioned for a total of $3,400.

The town was incorporated in 1881: on April 14, 1881, according to Wikipedia, and in 1881 according to the state’s historical census file. The County calls Castle Rock “a historic mining and ranching area that incorporated in 1881”.

The depot and the stone

The Denver & Rio Grande, which the Historical Society calls the first narrow-gauge line in the United States, was built between Denver and Old Colorado City by General William Jackson Palmer in 1871. Once Castle Rock was the county seat, its people pushed for a stop, and by 1875 the town had a small depot on Third Street, built of the rhyolite stone native to the area, with wide eaves on drop-pendant brackets and fine stonework at the corners, sills and lintels (the museum’s history). Wikipedia’s article on the depot names its builder, Benjamin Hammar, who also built the original Denver Union Terminal and is buried in Castle Rock, and quotes it as a rare example of a stone depot built by the railroad.

The stone was an industry of its own. In the late 1800s and early 1900s, Wikipedia says, Castle Rock had a very active rhyolite-quarrying industry, and many immigrants came to work in the quarries; the depot is built of stone from them.

The depot outlasted the trains. In 1970 Bill and Joyce Murray bought it, moved it from trackside to 420 Elbert Street and restored it, keeping the old ticket window, the baggage area and the names of railroad employees written on the wall 150 years ago. It went on the National Register of Historic Places in 1974 and the Castle Rock Register of Local Landmarks in 1994 (Historical Society).

The courthouse and the old town

The county courthouse of 1889–1890 burned on March 11, 1978; Wikipedia says the fire was arson. It had been added to the National Register in December 1976 and was removed in August 1978, the register list records, with its address as 301 Wilcox Street.

Seven Castle Rock buildings have been on the register. Besides the courthouse and the depot, they are Castle Rock Elementary School at Third and Cantril streets (listed in 1984), the Benjamin Hammar House at 203 Cantril Street (1993), the First National Bank of Douglas County at 300 Wilcox Street, built in 1904 to a design by George Louis Bettcher (1995), the Keystone Hotel at 219 and 223 Fourth Street (1997) and the Samuel Dyer House at 208 North Cantril Street (2016). Cedar Hill Cemetery, founded in 1875, is the only cemetery in Castle Rock and holds pioneers of the early town and county.

The star on the Rock

In 1936, Wikipedia records, the town was given land that included the butte, and men employed by the Works Progress Administration built a star on top of it. It was lit every year from 1936 to 1941, then left dark during the Second World War as a symbol of sacrifice. On August 14, 1945, just after V-J Day, it was made into a V for victory, and on December 7, 1945, it was lit for the holidays again; it has been lit every year since.

The Chamber of Commerce, which also gives 1936 as the year the star was first lit, created the Starlighting in 1962 to open the holiday season with the lighting, and part of the tradition is a reading of “Castle Rock,” a poem written in 1966 by resident Helen Lowrie Marshall. This year’s Starlighting is on Saturday, November 21, downtown; the star is lit at about 5:30 pm, followed by fireworks.

A small town for eighty years

The census counted 88 people in 1880, the year before incorporation, and 315 in 1890 (state historical census). For the next half century it grew slowly: 304 in 1900, 461 in 1920, 580 in 1940, 741 in 1950. Then it began to climb, to 1,152 in 1960, 1,531 in 1970 and 3,921 in 1980.

The Historical Society was formed in 1991 by residents who wanted to highlight the town’s history and preserve the historic buildings at the heart of downtown, and in its early years it ran house tours in the historic Craig and Gould neighborhood. In 1996 it bought the old depot, and with a State Historical Fund grant and gifts from businesses and the Town it opened the Castle Rock Museum there in October 1997.

The boom

Between 1980 and 2020 the town grew almost nineteen-fold: 8,708 people in 1990, 20,224 in 2000, 48,231 in 2010 and 73,158 in 2020 (state historical census). The state demographer’s estimate for 2024, prepared in October 2025, is 83,497 (county and municipal time series). Wikipedia calls Castle Rock the most populous municipality in Douglas County and the most populous place in Colorado that is a town rather than a city.

The town changed how it governs itself on the way. After financial difficulties in the early 1980s, voters approved a charter amendment in 1984 that authorized a home-rule charter commission, and the home-rule charter was finalized in 1987. The County describes the government as council-manager.

The town’s name is also known in law. In Town of Castle Rock v. Gonzales, decided on June 27, 2005, the U.S. Supreme Court ruled 7–2 that the town and its police department could not be sued under federal civil-rights law for failing to enforce a restraining order. The case arose from the 1999 murders of Jessica Gonzales’s three daughters by their father, after Castle Rock police declined her requests to enforce the order.

Where to see it

The Castle Rock Museum in the depot at 420 Elbert Street is open Wednesday to Friday from noon to 5 and Saturday from 11 to 4 (303-814-3164). The Historical Society’s events page lists free downtown walking tours once a month from May to September, from The Courtyard at 333 Perry Street to the museum; a free walk through Cedar Hill Cemetery, held this year on October 3; and Ghostly Stories and Tragic Tales walking tours on October evenings at 7 and on the afternoons of October 17 and 31 at 1, free but by reservation. The Society has also put cast-aluminum markers with QR codes on historic buildings around town, each linking to the building’s story; its page gives the number as 24 in one sentence and 21 in the next, and anyone who visits them all can collect a certificate at the museum.

For deeper research, the Douglas County Libraries’ Archives & Local History is in the Philip & Jerry Miller Library at 100 S. Wilcox Street, where staff help with historical, archival and family-history projects and where, the library says, you can learn about its namesakes and benefactors, Philip and Jerry Miller.