Resident Population in Trinity County, CA was 15.67000 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Trinity County, CA reached a record high of 16.08900 in January of 2020 and a record low of 7.61500 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Trinity County, CA - last updated from the United States Federal Reserve on May of 2024.