Canby

Modoc County is California's far-northeast-corner county (population ~8,700, the second-least populous CA county after Alpine), bordered by Oregon to the north and Nevada to the east. The county seat is Alturas (the only incorporated city, population ~2,700). The county is dominated by federal land - the Modoc National Forest, Lava Beds National Monument, Modoc National Wildlife Refuge, BLM Surprise Resource Area, and Clear Lake National Wildlife Refuge together cover the great majority of land area. Unincorporated communities include Adin, Cedarville, Eagleville, Fort Bidwell, Lake City, Likely, Lookout, New Pine Creek, Tulelake (which sits partially in Siskiyou County, with most population in Siskiyou), and the Newell-Tulelake corridor area. The county Board of Supervisors administers ADUs in unincorporated areas under California Government Code Sec. 65852.2 and 65852.22 (state ADU preemption, as amended by AB 68/881, SB 13, AB 670/3182, AB 2221/SB 897, AB 976, and AB 1033). The county code addresses ADUs through ministerial 60-day review consistent with state preemption. Practical permitting frictions are dominated by federal-land adjacency (most parcels abut Forest Service or BLM land), severe winter snow loads at high desert elevation (~4,500 ft to 6,000+ ft), short construction season (typical practical window is May to October), and septic/well dependence outside the small Alturas service area.

• Modoc County Code Title 11 - Zoning, ADU/JADU provisions
• Cal. Gov't Code Sec. 65852.2 (Accessory Dwelling Units)
• Cal. Gov't Code Sec. 65852.22 (Junior Accessory Dwelling Units)

State-floor overlay: California state ADU preemption applies in full. AB 1033 condo-conversion election is at the county's option and Modoc County has not adopted it as of last check. AB 976 prohibits owner-occupancy mandates on detached ADUs through 2025 expiry. HCD oversight: any county ordinance amendment must be submitted to HCD within 60 days of adoption per Sec. 65852.2(h). Federal lands (Modoc NF, Lava Beds NM, Modoc NWR, BLM Surprise) are outside county zoning - residential structures on federal land require federal special-use authorization, not county building permits.

Modoc County overlays of consequence: extensive federal land coverage (Modoc National Forest, Lava Beds National Monument, Modoc National Wildlife Refuge, BLM Surprise Resource Area, Clear Lake National Wildlife Refuge - together covering the majority of the county and outside county zoning entirely); CAL FIRE State Responsibility Area along Warner Mountains and Devils Garden (Very High and High FHSZ); FEMA SFHA along the Pit River, North Fork Pit River, South Fork Pit River, Goose Lake (intermittent), and Surprise Valley playas; greater sage-grouse priority habitat overlay across South Warner / Surprise Valley sagebrush-steppe (federal candidate-species consultation potential); Williamson Act ranching contracts in Surprise Valley and Big Valley; and the seasonally-flooded Tule Lake / Lower Klamath agricultural-lease parcels in the western corner straddling the Siskiyou County line.

• Modoc National Forest / Lava Beds National Monument / Modoc NWR / BLM Surprise / Clear Lake NWR
• CAL FIRE State Responsibility Area / Warner Mountains and Devils Garden FHSZ
• FEMA SFHA - Pit River, Goose Lake, Surprise Valley playas
• Greater sage-grouse priority habitat (South Warner / Surprise Valley)
• Williamson Act ranching contracts - Surprise Valley and Big Valley

The Modoc County Planning and Building Department issues all ADU permits in unincorporated areas (the great majority of the county outside Alturas city limits). Practical permitting frictions: federal-land adjacency (most private parcels are checkerboarded with or adjacent to Forest Service / BLM land - access easements, fire-defensible-space coordination with federal fire crews, and federal Endangered Species Act consultation may apply on parcels near sensitive habitat), severe winter snow loads (design loads of 50-90 psf depending on elevation), short construction window, septic/well dependence with deep groundwater requiring purpose-drilled wells in the South Warner / Surprise Valley areas, and very limited contractor availability (Alturas-based contractors are few; most projects rely on contractors traveling from Klamath Falls OR or Reno NV).