Lassen National Forest is a national forest located in northerneastern California with an area of 1,070,344 acres (1,672. "National forest" redirects here for the National Forest in England see National Forest England; for those in Brazil see List of Brazilian National Forests California ( is a US state on the West Coast of the United States, along the Pacific Ocean. 41 sq mi, or 4,331. 53 km²) surrounding Lassen Volcanic National Park. Lassen Volcanic National Park is a United States National Park in north eastern California. It lies in parts of Lassen, Shasta, Tehama, Plumas, and Butte counties. Lassen County is a county located in the northeastern portion of the U Shasta County is a county located in the northern portion of the U Tehama County (pronounced teh-HAY-muh is a county located in the northern part of the U Plumas County is a county located in the Sierra Nevada of the U Butte County is a County located in the Central Valley of the U [1] Forest headquarters are located in Susanville, California. Susanville is a city and county seat of Lassen County, California, USA