| Official Name: | Lake Sumner, New Mexico |
| Settlement Type: | Census-designated place |
| Mapsize: | 250px |
| Pushpin Map: | USA |
| Pushpin Map Caption: | Location in the United States |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | New Mexico |
| Subdivision Type2: | County |
| Subdivision Name2: | De Baca |
| Unit Pref: | Imperial |
| Area Footnotes: | [1] |
| Area Total Km2: | 177.48 |
| Area Land Km2: | 161.28 |
| Area Water Km2: | 16.20 |
| Area Total Sq Mi: | 68.53 |
| Area Land Sq Mi: | 62.27 |
| Area Water Sq Mi: | 6.25 |
| Population As Of: | 2020 |
| Population Total: | 72 |
| Population Density Km2: | 0.45 |
| Population Density Sq Mi: | 1.16 |
| Timezone: | Mountain (MST) |
| Utc Offset: | -7 |
| Timezone Dst: | MDT |
| Utc Offset Dst: | -6 |
| Elevation Ft: | 4252 |
| Coordinates: | 34.6186°N -104.38°W |
| Postal Code Type: | ZIP code |
| Postal Code: | 88119 |
| Area Code: | 575 |
| Blank Name: | FIPS code |
| Blank Info: | 35-37875 |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 2408553 |
Lake Sumner is a census-designated place (CDP) in De Baca County, New Mexico, United States. The population was 143 at the 2010 census,[2] up from the figure of 86 recorded in 2000.
Lake Sumner is located in northern De Baca County and surrounds Lake Sumner, a reservoir formed by Sumner Dam on the Pecos River. Sumner Lake State Park occupies the east and west sides of the lake at its south end, near the outlet. U.S. Route 84 forms the northeastern edge of the CDP; the highway leads southeast 10miles to Fort Sumner, the De Baca County seat, and northwest to Santa Rosa.
According to the United States Census Bureau, the CDP has a total area of 177.3km2, of which 161km2 is land and 16.3km2, or 9.17%, is water.[2]
According to the Köppen Climate Classification system, Lake Sumner has a cold semi-arid climate, abbreviated "BSk" on climate maps. The hottest temperature recorded at Lake Sumner was 112F on June 12, 2022, while the coldest temperature recorded was -24F on January 13, 1963.
As of the census[3] of 2000, there were 86 people, 44 households, and 27 families residing in the CDP. The population density was 1.4 people per square mile (0.5/km2). There were 188 housing units at an average density of 3.0/sq mi (1.2/km2). The racial makeup of the CDP was 90.70% White, 1.16% Asian, 3.49% from other races, and 4.65% from two or more races. Hispanic or Latino of any race were 17.44% of the population.
There were 44 households, out of which 18.2% had children under the age of 18 living with them, 61.4% were married couples living together, and 38.6% were non-families. 34.1% of all households were made up of individuals, and 13.6% had someone living alone who was 65 years of age or older. The average household size was 1.95 and the average family size was 2.48.
In the CDP, the population was spread out, with 14.0% under the age of 18, 4.7% from 18 to 24, 17.4% from 25 to 44, 33.7% from 45 to 64, and 30.2% who were 65 years of age or older. The median age was 52 years. For every 100 females, there were 120.5 males. For every 100 females age 18 and over, there were 111.4 males.
The median income for a household in the CDP was $25,250, and the median income for a family was $29,167. Males had a median income of $28,750 versus $23,750 for females. The per capita income for the CDP was $17,590. There were no families and 10.5% of the population living below the poverty line, including no under eighteens and 45.5% of those over 64.
Fort Sumner Municipal Schools is the school district of all of De Baca County.[4]