3 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Fort Sumner | 1 | 852 | 883 | -0.58% | 257 | 3 | Village |
| Fort Sumner | 2 | 852 | 875 | -0.58% | 257 | 3 | Village |
| Lake Sumner | 3 | 63 | 17 | -7.35% | 1 | 62 | CDP |
Fort Sumner is the largest city in De Baca County, with a population of 852.
Lake Sumner is the smallest city in De Baca County, with a population of 63.
There are 3 cities in De Baca County, New Mexico.