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California County
Mono County, California
Mammoth Mountain and the ancient Mono Lake - from Mammoth Mountain Ski Area (the highest-elevation major ski resort in California at a 11,053-foot summit, receiving an average of 400 inches of snow annually and consistently ranking among the top ski destinations in the United States) to Mono Lake (a 760,000-year-old saline lake whose eerie calcium carbonate tufa towers rise from alkaline waters supporting one of the world's most productive brine shrimp ecosystems and 85% of California's nesting population of California gulls) and the active Mammoth Mountain volcanic field - a county of extraordinary natural drama where geothermal activity, ancient geology, and world-class skiing coexist in the eastern Sierra's rain shadow.
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Office: Mono County OES – (760) 924-1830 | monocounty.ca.gov
Alert System: Mono County Alert; CA Alert; NOAA Weather Radio
Shelter Info: Mammoth Lakes Community Center; school facilities; contact OES
FEMA Region: Region 9
Notes: Eastern Sierra Nevada county; Bridgeport is county seat (small); Mammoth Lakes is the county’s dominant population center and primary ski resort; Long Valley Caldera (ACTIVE VOLCANIC SYSTEM – potentially the most dangerous in the contiguous US; Mammoth Mountain sits on the edge of the caldera; CO2 tree kills and ground deformation are monitored continuously by USGS; volcanic unrest in 1982 prompted evacuation concerns); earthquake risk (Long Valley area highly seismically active; 2020 Mammoth Lakes earthquakes); severe winter conditions; avalanche risk; wildfire risk in summer
Roads & Utilities
ROADS & TRANSPORTATION
County Roads: Mono County Public Works – (760) 932-5440
Transit: Eastern Sierra Transit Authority (ESTA) – (760) 872-1901; Mammoth Lakes Transit; limited service; very auto-dependent; seasonal
Airport: Mammoth Yosemite Airport (MMH – Alaska Airlines seasonal service to LAX and SFO – one of the highest elevation commercial airports in the US at 7,135 ft); Reno/Tahoe International accessible
Notes: US-395 is the county’s lifeline running north-south through the Eastern Sierra; SR-203 (Mammoth Lakes Road) connects US-395 to Mammoth Mountain; Hwy 120 (Tioga Road – closed in winter) connects Yosemite to US-395 at Lee Vining (Mono Lake); the county’s isolation in winter (passes often closed by snow) can be extreme; Mammoth Mountain Ski Area is the county’s economic engine
Business & Permits
BUILDING & PERMITS
Office: Mono County Planning – (760) 924-1800 | monocounty.ca.gov
Services: County permits; Mammoth Lakes (separate – very active for ski resort community), Bridgeport, Lee Vining, June Lake have county permits
Notes: Mammoth Lakes is one of California’s most active ski resort development markets; ski lodge, condo, and vacation rental construction is significant; volcanic hazard zone restrictions in some areas; LADWP owns significant land in the county (Owens Valley water rights extend into Mono County at the Mono Lake watershed)
Veterans Services
VETERANS SERVICES
Office: Mono County Veterans Services – (760) 924-1830
VA Medical: VA Reno, NV – most accessible; Sacramento VA (very distant); Fresno VA CBOC accessible seasonally
Services: Benefits claims, VA healthcare; very limited local resources
Notes: Remote Eastern Sierra county; VA access requires significant travel; ski resort employees include some veterans; telehealth important in this remote county
Libraries
LIBRARIES
System: Mono County Library – (760) 924-1707 | monocounty.ca.gov/library
Branches: Mammoth Lakes, Bridgeport, Lee Vining, June Lake, Coleville
Services: Books, public computers, Wi-Fi, children’s programs; Eastern Sierra history; Mono Lake heritage
Notes: Small library system serving a dispersed mountain community; Mammoth Lakes branch serves the ski resort community; Lee Vining branch serves the Mono Lake gateway community; the library serves both permanent residents and a large seasonal worker population
Parks & Recreation
PARKS & RECREATION
Key Assets: Mammoth Mountain Ski Area (one of California’s premier ski resorts – 3,500+ acres; frequently the deepest snowpack in California; iconic ski culture since 1955; mountain biking in summer); Mono Lake (one of California’s most otherworldly landscapes – ancient alkaline lake with bizarre tufa towers; one of the most important migratory bird stops in the Western US; the 1994 Mono Lake water rights case forced LA to reduce diversions and allow the lake to refill); Devils Postpile National Monument (bizarre basalt columnar formation; accessible via shuttle from Mammoth; Rainbow Falls); Bodie State Historic Park (one of the best-preserved ghost towns in the US – Bodie was a gold rush boomtown of 10,000 people; now frozen in time with buildings, machinery, and artifacts preserved in “arrested decay” state); Ansel Adams Wilderness; John Muir Wilderness; Yosemite NP (via Tioga Road – seasonal); Hot Creek Geologic Site (boiling hot springs in a stream – dramatic but dangerous; thermal features)
Notes: Mono County packs extraordinary attractions into a small, remote county; Mono Lake is scientifically and legally significant (the 1994 State Water Resources Control Board decision to require LA to reduce diversions to allow the lake to refill was a landmark in California water law and environmental history); Bodie is one of the most atmospheric places in California – wandering the empty streets and looking through windows at furniture, dishes, and artifacts left when miners departed is genuinely haunting; Devils Postpile’s hexagonal basalt columns (formed by cooling lava) are geometrically perfect; Mammoth Mountain offers California’s finest Sierra skiing
GIS & Maps
GIS & MAPS
GIS Portal: Mono County GIS – monocounty.ca.gov; USGS Long Valley Caldera monitoring maps; Mammoth Mountain volcanic hazard maps; CalFire maps; NPS maps (Devils Postpile; Yosemite)
Notes: USGS Volcano Hazards Program maintains continuous monitoring and GIS for Long Valley Caldera – one of the most intensively studied volcanic systems in the US; avalanche hazard maps for Mammoth; Mammoth Mountain ski area trail maps; Mono Lake basin hydrology mapping
Animal Services
ANIMAL SERVICES
Shelter: Mono County Animal Control – (760) 932-5450
Services: Basic animal control; wildlife management (mule deer, pronghorn, black bears, mountain lions, Sierra Nevada bighorn sheep – federally threatened)
Notes: Sierra Nevada bighorn sheep recovery program (federally threatened; managed by CDFW) is significant in the Mono County high Sierra; pronghorn antelope in the high desert sage; mule deer migrations; mountain lion management; High Sierra golden eagle population; volcanic CO2 kills trees and can affect wildlife in some areas near Mammoth Mountain; bear management in the Mammoth Lakes resort community
Environmental & Waste
ENVIRONMENTAL / WASTE MANAGEMENT
Solid Waste: Mono County Public Works – (760) 932-5440; Mammoth Lakes solid waste (significant volume during ski season)
Environmental: California SWRCB; Lahontan RWQCB; USGS Volcano Hazards Program (Long Valley Caldera monitoring); LADWP (Mono Lake water diversions – under SWRCB restrictions); NPS (Devils Postpile); USFS (Inyo NF – most of the county’s forest land); Sierra Nevada Conservancy
Notes: Long Valley Caldera is one of California’s most significant volcanic hazards – a super-eruption approximately 760,000 years ago covered much of the western US in ash; current activity (CO2 emissions, ground deformation, seismic swarms) is monitored continuously by the USGS Long Valley Observatory; the Mammoth Mountain CO2 emissions zone (several areas of the ski mountain where CO2 seeps from the ground at concentrations high enough to kill trees and potentially asphyxiate people in confined areas) is marked and monitored; Mono Lake’s restoration following the landmark 1994 water rights decision is one of California’s great environmental success stories – the lake has risen approximately 15 feet from its low point and the alkali fly and brine shrimp populations have partially recovered; LADWP continues to divert some water under the 1994 limits; the Eastern Sierra’s limited water supply is fully appropriated and contested
About Mono County
Mono County is the eastern Sierra’s recreational and geological showcase – a county where active volcanic fields, one of the world’s oldest lakes, and California’s premier ski resort share a spectacular high-desert landscape.
Mammoth Lakes (population ~8,000) is the county’s largest city and dominant economic engine – a resort community built around Mammoth Mountain Ski Area that attracts over one million skiers annually in winter and reinvents itself as a hiking, mountain biking, and fishing destination in summer. Mammoth Mountain sits on a resurgent dome of the Long Valley Caldera – a massive volcanic system that erupted catastrophically 760,000 years ago and remains geothermally active.
Mono Lake – preserved by a landmark 1994 California State Water Board decision that stopped Los Angeles from diverting its tributary streams – is one of North America’s most significant saline lakes. The lake’s tufa towers (calcium carbonate formations created where freshwater springs met the alkaline lake water) are among the most photographed geological features in California.
Bridgeport (the county seat, population ~500) is one of California’s most remote county seats – a ranching community at 6,500 feet elevation in the Bridgeport Valley.
All Services
Browse every category and topic available for this county.
The Mono County Assessor at 74 School Street, Bridgeport, CA 93517, phone 760-932-5510, assesses under Proposition 13 rules. No CA estate tax.
Courts & Legal
Mono County Superior Court at 74 School Street, Bridgeport, CA 93517, phone 760-932-5530, handles probate.
Marriage & Vital Records
Marriage licenses, divorce records, and birth & death certificates are handled by the following office(s):
CLERK-RECORDER (Deeds, Marriage Licenses)
25 Bryant St., Bridgeport, CA 93517
(760) 932-5537
County Clerk
(760) 932-5537
Genealogy
County-level record sources
Mono County Superior Court, both courthouses (marriage licenses, will and estate case files – see Probate section above)
Local societies
No dedicated Mono County genealogical society was confirmed in available directories.
Probate & Estate
Losing someone and having to deal with courts and paperwork at the same time is hard. This section won’t make that easier, but it should tell you what to expect, what it costs, and where to go – so at least you’re not walking in blind.
Where to go
Mono County has two courthouse locations – file in whichever is more convenient.
California recently increased its small-estate thresholds substantially, so check this first – more estates now qualify to skip full probate than in past years.
Small Estate Affidavit (personal property) – for estates with personal property valued at $208,850 or less (for deaths on or after April 1, 2025; holds through March 31, 2028). No court filing needed – present the signed affidavit directly to the bank or institution holding the property. Must wait at least 40 days after the death, and no probate proceeding can already be pending.
Petition to Determine Succession to Real Property, Primary Residence – for a decedent’s primary California residence valued at $750,000 or less (Judicial Council Form DE-310). Requires a 40-day wait, notice to heirs, and a probate referee appraisal.
Affidavit for Real Property of Small Value – for other (non-primary-residence) California real property valued at $69,625 or less (Form DE-305). Requires a 6-month wait.
Formal Probate – required when the estate exceeds these thresholds. California typically uses the Independent Administration of Estates Act (IAEA), letting the personal representative handle most matters without a court hearing for each step.
California is a community property state – a surviving spouse already owns their half of community property, and can often use a simplified Spousal Property Petition (Form DE-221) instead.
If using the small estate affidavit (personal property)
Wait at least 40 days after the death.
Confirm total qualifying California personal property (excluding trust assets, joint tenancy, POD/TOD accounts, and beneficiary-designated accounts) is $208,850 or less, using date-of-death values.
Complete the affidavit under Probate Code § 13100.
Present it with a certified death certificate directly to the bank or institution – no court filing required. Collecting property this way makes you personally liable for the decedent’s unsecured debts up to the value received (Prob. Code § 13109).
IF USING THE PRIMARY RESIDENCE PETITION OR SMALL REAL PROPERTY AFFIDAVIT
Confirm the property qualifies and the applicable waiting period has passed (40 days for the primary-residence petition; 6 months for the small real property affidavit).
File the petition (Form DE-310) or affidavit (Form DE-305) with the Mono County Superior Court, at either courthouse.
A probate referee appraises the property; heirs receive notice.
Once approved, the property transfers without full probate administration.
If formal probate is required
Deliver the original will (if any) to the court clerk within 30 days of learning of the death (Prob. Code § 8200).
File a Petition for Probate (Form DE-111) to admit the will and request appointment as personal representative.
The court issues Letters Testamentary (Form DE-150) or Letters of Administration.
If Independent Administration authority is granted, the personal representative can act on most matters without separate court hearings.
Notice to creditors and an inventory/appraisal (with a probate referee) follow, along with payment of debts and taxes.
The estate closes with a final petition for distribution.
What it costs
Small estate affidavit / real property affidavits: no court filing fee for the personal-property affidavit; filing fees apply to the DE-310 primary-residence petition and DE-305 small real property affidavit.
Formal probate filing fee: several hundred dollars, varying somewhat by county.
Personal representative and attorney compensation: statutory fee schedule based on estate size (Prob. Code §§ 10800–10810) – a percentage that declines as the estate grows.
No California state estate tax or inheritance tax.
Probate filings, estate administration, and guardianship matters are handled by the following office(s):
Public Safety & Arrests
Arrest records, inmate search, and law enforcement services are handled by the following office(s):
SHERIFF
25 Bryant St., Bridgeport, CA 93517
(760) 932-7549
Elections & Voting
Voter registration, polling locations, and elections information are handled by the following office(s):
CA Voter Registration
Health & Human Services
Offices & Contacts
Health services, social services, and assistance programs are handled by the following office(s):
Health Dept
(760) 924-1830
Medi-Cal
(800) 300-1506
Tribal Health
Bridgeport Indian Colony; Benton Paiute; Bishop Paiute Tribe (shared border)
Public Health Information
PUBLIC HEALTH
Office: Mono County Health Department – (760) 924-1830
Services: Immunizations, WIC, STI testing, environmental health, vital records; behavioral health; volcanic hazard health monitoring; altitude illness education
Hospital: Mammoth Hospital – (760) 934-3311 (small but well-equipped for a ski resort community; orthopedic surgery capabilities are strong given ski injury prevalence); Reno or Fresno for major care
Notes: Mammoth Hospital is well-equipped for orthopedic injuries (ski and snowboard injuries); altitude illness (Mammoth is at 7,953 ft elevation) affects visitors from sea level; CO2 volcanic emissions create localized health hazards near Mammoth Mountain; behavioral health for seasonal workers; very high cost of living affects healthcare worker recruitment
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