The Round Valley Indian Reservation is a federally recognized Indian reservation lying primarily in northern Mendocino County, California, United States. A small part of it extends northward into southern Trinity County. The total land area, including off-reservation trust land, is 93.939 km. More than two-thirds of this area is off-reservation trust land, incl…The Round Valley Indian Reservation is a federally recognized Indian reservation lying primarily in northern Mendocino County, California, United States. A small part of it extends northward into southern Trinity County. The total land area, including off-reservation trust land, is 93.939 km. More than two-thirds of this area is off-reservation trust land, including about 405 acres in the community of Covelo. The total resident population as of the 2000 census was 300 persons, of whom 99 lived in Covelo.