Modoc County

The county in brief

A traveler's read on Modoc County

Seven hundred lava-tube caves underlie Lava Beds National Monument in northern Modoc County — the largest concentration of lava tubes anywhere in the contiguous United States, formed by basaltic flows from the Medicine Lake shield volcano (the largest-volume volcano in the Cascade Range per USGS Cascades Volcano Observatory). Twenty-four caves are open for self-guided public exploration (BYO helmet plus two independent light sources per NPS Lava Beds Cave Use regulations), and the Cave Loop Road from the visitor center accommodates rigs to 30 ft on a 2.6-mile one-way paved circuit. Modoc County is the most northeastern county in California and the only California county with no railroad service of any kind — a function of being walled off from the rest of California by the Warner Mountains to the east (peaking at Eagle Peak 9,892 ft inside the South Warner Wilderness) and the Cascade Range to the west. The 3,944-sq-mi county runs only 8,700 residents per 2020 Decennial Census (2.2 persons per sq mi), and Alturas (population 2,715) is the only town with a full grocery, propane, and diesel within 75 miles.

CA-299 from Alturas to Cedarville (the Surprise Valley basin-and-range crossing) is the only paved east-west route, and Cedar Pass at 6,305 ft closes occasionally to oversized loads during winter storms per Caltrans District 2 chain control. Modoc National Forest dispersed camping at the South Warner Wilderness perimeter (Patterson, Pepperdine, and Cedar Pass trailheads) accepts rigs to 30 ft under the standard 14-day stay limit, with food-storage orders active May-October per Forest Order 09-2024. The Pacific Flyway routes 80% of all North American snow-goose migration through Modoc NWR (Tule Lake and Lower Klamath NWR straddle the county line into Siskiyou) — peak fall counts exceed 1.5 million birds per US Fish & Wildlife Service refuge surveys. The 1872-73 Modoc War (the only major US Army campaign fought entirely inside California) ended at Captain Jack's Stronghold inside what is now Lava Beds NM, a self-guided 2-mile interpretive trail accessible from the monument's north entrance.