| Official Name: | New Castle, Colorado |
| Settlement Type: | Town |
| Motto: | "Authentically Colorado" |
| Mapsize: | 250px |
| Subdivision Type: | Country |
| Subdivision Type1: | State |
| Subdivision Type2: | County |
| Subdivision Name2: | Garfield County[1] |
| Government Type: | Home rule municipality |
| Leader Title: | Mayor |
| Established Title2: | Incorporated (town) |
| Established Date2: | March 27, 1890[2] |
| Unit Pref: | Imperial |
| Area Footnotes: | [3] |
| Area Total Km2: | 6.75 |
| Area Land Km2: | 6.52 |
| Area Water Km2: | 0.23 |
| Area Total Sq Mi: | 2.61 |
| Area Land Sq Mi: | 2.52 |
| Area Water Sq Mi: | 0.09 |
| Population As Of: | 2020 |
| Population Footnotes: | [4] |
| Population Total: | 4923 |
| Population Density Km2: | auto |
| Population Density Sq Mi: | auto |
| Timezone: | Mountain (MST) |
| Utc Offset: | -7 |
| Timezone Dst: | MDT |
| Utc Offset Dst: | -6 |
| Coordinates: | 39.5722°N -107.535°W |
| Elevation Ft: | 5811 |
| Postal Code Type: | ZIP code[5] |
| Postal Code: | 81647 |
| Area Code: | 970 |
| Blank Name: | FIPS code |
| Blank Info: | 08-53395 |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 2413042 |
The Town of New Castle is a home rule municipality in Garfield County, Colorado, United States. The population was 4,923 at the 2020 census.
When New Castle was incorporated in 1888, its economy was largely based on mining coal that was needed by the silver-mining industry to fire silver smelters. On February 18, 1896, a methane explosion in the Vulcan Mine killed 49 men and started a coal fire that was still burning as of 2020. The Vulcan reopened and suffered additional explosions on December 12, 1913 (killing 37) and November 4, 1918 (killing 3).[6]
There are at least 25 coal fires burning near the town.[7] They are normally confined underground.
From 2000 - 2014 the population grew 129%, much higher than the average growth in Colorado over the same period (20.8%).[8]
New Castle is located on the north side of the Colorado River, just east of where the river cuts through the Grand Hogback. Interstate 70 passes by the town following the river, with access from Exit 105. I-70 leads east to Glenwood Springs, the county seat, east to Denver, and west to Grand Junction. U.S. Route 6 is Main Street in New Castle and forms a parallel route to I-70 for local traffic. US-6 joins I-70 5miles to the east at Chacra and to the west at a point west of Rifle.
According to the United States Census Bureau, the town has a total area of 7km2, of which 6.9km2 is land and 0.1km2, or 1.21%, is water.[9]
New Castle is within Garfield Re-2 School District.[10] The town is home to two elementary schools, a middle school, and a high school: