Modoc National Forest, National forest in northeastern California, United States.

Modoc National Forest is a large protected area in northeastern California featuring forests and open landscapes shaped by geology. The terrain shows volcanic formations, pine stands, sagebrush grasslands, wetland areas, and mountain ranges with desert characteristics.

Modoc National Forest was established as the Modoc Forest Reserve on November 29, 1904, by the United States General Land Office. It was named for the Modoc people whose territory traditionally covered this area. In 1905 federal forests passed to the U.S. Forest Service, and on March 4, 1907, they became National Forests. On July 1, 1908, Warner Mountains National Forest was added to Modoc.

The forest is named for the Modoc people, whose traditional territory covered this area of northeastern California. The name was carried over when the Modoc Forest Reserve was created in 1904, and it remains the everyday label for the land around Alturas, Adin, Cedarville and Tulelake.

Forest headquarters are in Alturas, with ranger district offices in Adin, Alturas, Cedarville and Tulelake. The Warner Mountains rise in the eastern part, where the eastern slopes drop steeply and the western flank is gentler. The northern end of the forest takes in about two thirds of Goose Lake.

Most of the forest lies atop immense lava flows that built up over the last 500,000 years, and the eastern part east of Alturas holds the Warner Mountains, whose eastern slopes drop steeply while the western flank is gentler. The forest spans 1,654,392 acres across Modoc, Lassen and Siskiyou counties.