Resident Population in Los Alamos County, NM was 19.44400 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Los Alamos County, NM reached a record high of 19.44400 in January of 2023 and a record low of 15.00000 in January of 1972. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Los Alamos County, NM - last updated from the United States Federal Reserve on May of 2024.